                             PUBLISHED

UNITED STATES COURT OF APPEALS
                 FOR THE FOURTH CIRCUIT


DAVID BRYTE, Personal                    
Representative of the Estate of Lova
E. Bryte, deceased; DAVID BRYTE;
KATHY B. SMITH; JAMES B. SMITH;
M. E. SMITH, a minor, by and
through her legal guardian, Kathy
B. Smith; DONNA J. MILLER,
                Plaintiffs-Appellants,
                  v.
                                               No. 04-1051
AMERICAN HOUSEHOLD,
INCORPORATED, formerly known as
Sunbeam Corporation; SUNBEAM
PRODUCTS, INCORPORATED,
              Defendants-Appellees,
                 and
SEARS ROEBUCK AND COMPANY,
                      Defendant.
                                         
           Appeal from the United States District Court
       for the Northern District of West Virginia, at Elkins.
            Richard L. Williams, Senior District Judge.
                          (CA-00-93-2)

                         Argued: May 26, 2005

                       Decided: November 21, 2005

  Before WIDENER, NIEMEYER, and LUTTIG, Circuit Judges.



Affirmed by published opinion. Judge Widener wrote the opinion, in
which Judge Niemeyer and Judge Luttig concurred.
2                BRYTE v. AMERICAN HOUSEHOLD, INC.
                              COUNSEL

ARGUED: William J. Hansen, MCDERMOTT, HANSEN &
MCLAUGHLIN, Denver, Colorado, for Appellants. Stephen Thomas
Moffett, MOFFETT & DILLON, Birmingham, Michigan, for Appel-
lees. ON BRIEF: George E. McLaughlin, MCDERMOTT, HANSEN
& MCLAUGHLIN, Denver, Colorado, for Appellants. John E. Hall,
John H. Williams, Jr., ECKERT, SEAMANS, CHERIN & MEL-
LOTT, P.L.L.C., Morgantown, West Virginia; Thomas Vitu, MOF-
FETT & DILLON, Birmingham, Michigan, for Appellees.


                              OPINION

WIDENER, Circuit Judge:

   On October 23, 2000, Lova Bryte died in a fire in her Preston
County, West Virginia apartment. She was using an electrically
heated throw at the time of the fire. Several weeks later, plaintiffs,
Mrs. Bryte’s personal representative and relatives, brought this action
against defendant American Household, Inc. (formerly Sunbeam
Corp.), the manufacturer of the throw. Plaintiffs alleged that the elec-
tric throw had a defective safety circuit and that this defect caused the
deadly fire. At trial, the district court excluded various evidence,
including expert testimony, offered by plaintiffs to prove the causa-
tion and defect elements of their claims. At the close of plaintiffs’
case, the district court granted defendant’s motion for judgment as a
matter of law on the ground that plaintiffs had not established suffi-
cient evidence of causation. Plaintiffs appeal from the district court’s
evidentiary rulings and the ensuing judgment for defendant. We
affirm.

                                   I.

   Though the record on appeal is extensive, the basic facts of this
case are not disputed. Mrs. Bryte had begun using the electric throw
in question about two years before the fire occurred, after having suf-
fered a stroke. As a result of her stroke, Mrs. Bryte could not pick
herself up from her recliner without assistance, and her movement
                  BRYTE v. AMERICAN HOUSEHOLD, INC.                     3
was limited to shifting in the chair. Also as a result of her stroke, Mrs.
Bryte used the electric throw throughout the year to keep warm when
sitting in her recliner. Typically, she would have had placed over her
a blanket or afghan and the throw would be laid on top of the blanket.
When in use, the electric throw would be plugged directly in to a wall
outlet on Mrs. Bryte’s left. When not in use, the throw was draped
over the back of the recliner or a love-seat. The throw had not mal-
functioned and there was no visible damage to it or its power cord.

   Other than the recliner, the living room of Mrs. Bryte’s apartment
contained a love-seat, a television and VCR, a coffee table, a tele-
phone, and a small table to the right of the recliner, which table had
a lamp and a candle on it. Mrs. Bryte did not smoke.

   The morning of the fire, Mrs. Bryte and her care-giver, Donna Mil-
ler, were in the apartment alone. During the late morning or early
afternoon, Mrs. Miller assisted Mrs. Bryte into the recliner and then
retrieved the electric throw from the back of the love-seat. Mrs. Miller
covered Mrs. Bryte with a blanket, then with the throw, plugged the
throw in to a wall outlet to the left of the recliner, and turned it on
to the low setting. The throw was not tucked in around Mrs. Bryte’s
sides. The power cord extended, at Mrs. Bryte’s feet, from the throw,
and the temperature control rested on the floor to Mrs. Bryte’s left
below her feet. Mrs. Bryte did not adjust the temperature control her-
self. At around 11 a.m., Mrs. Miller had lighted the candle that sat on
the small table to the right of the recliner. According to Mrs. Miller,
at that time the candle was partly burned, and, as far as she saw, the
flame had not extended above the rim of the glass candle container.
Mrs. Miller also testified that Mrs. Bryte was unable to reach the can-
dle, or the lamp that also was on the table. Mrs. Bryte could, however,
reach a part of the table for such things as a denture cup, a Star maga-
zine, a cookbook, a Bible and her glasses.

   Mrs. Miller left the apartment at 1:55 p.m. to pick up Mrs. Bryte’s
granddaughter from school, leaving the candle lighted and the electric
throw turned on. Mrs. Miller returned to the apartment at, she esti-
mated, 2:08 p.m., at which time she heard Mrs. Bryte calling for help.
Upon entering the apartment, Mrs. Miller saw smoke and fire coming
up the left side of Mrs. Bryte’s recliner and heard "snapping and
cracking." Mrs. Miller did not see any flames related to the power
4                BRYTE v. AMERICAN HOUSEHOLD, INC.
supply cord of the electric throw and she could not identify more spe-
cifically the source of the flames, other than the fact that the flame
was "down beside [Mrs. Bryte’s] chair and up on her leg." Mrs. Miller
tried, but was unable, to extinguish the fire. While in the apartment,
however, Mrs. Miller was able to see that the candle was still lighted
and that neither it nor the lamp had been moved or overturned. The
flames and smoke forced Mrs. Miller to flee the apartment to get the
children out.

   Shortly after the fire was extinguished, and before the removal of
Mrs. Bryte’s remains, Assistant State Fire Marshall Mack Dennis was
called to the scene. At that time, Dennis had been employed by the
West Virginia State Fire Marshall’s Office as a cause and origin
investigator for over 20 years. While he was not certified as a fire
investigator, he had attended numerous courses in arson and explosive
investigation. Dennis’ investigation of the fire scene traced the fire’s
path, starting from Mrs. Bryte’s left side and moving around the
room. Dennis took photographs of the fire scene and made a not-to-
scale diagram of the room where the fire occurred, which located the
large artifacts in the room. Dennis took oral, not written, statements
from the witnesses to the fire.

   Dennis’ diagram did not indicate the wall outlets located in the
room. He did observe, however, that the wall outlet immediately to
Mrs. Bryte’s left "had an electrical service cord plugged into it, and
the remains of that cord came over to Mrs. Bryte and was [sic] laying
across her arm." Dennis’ report later characterized the cord as
"wrapped around" Mrs. Bryte’s left arm. He did not measure the cord
or the exact distance between the wall outlet to her left and Mrs.
Bryte’s body, but approximated the distance to be "two and a half
feet." Dennis did not recover or photograph the service cord that he
saw draped across Mrs. Bryte’s body. Indeed, Dennis did not know
at first what this cord was for; only later, after speaking with family
members and Mrs. Miller, did he learn that Mrs. Bryte had been using
an electric throw at the time of the fire.

  Dennis did not know that there was a lamp, or observe any other
cord, plugged in to the same wall outlet as the cord found on Mrs.
Bryte. But there was another cord, an extension cord running from a
wall outlet behind the chair, to the lamp on the table. Moreover, he
                  BRYTE v. AMERICAN HOUSEHOLD, INC.                     5
did not inspect the outlet’s wiring. Dennis nonetheless excluded the
outlet, and also the table, candle, and lamp as potential origins of the
fire based on his discussions with Mrs. Miller and family members.
Also, he made this determination without knowing how the candle
had been lighted.

   Dennis’ only report, issued the day of the fire, concluded that the
cause of the fire was "improper use of an electric blanket." Specifi-
cally, Dennis recorded Mrs. Miller as having told him that the electric
throw was "around" Mrs. Bryte. Dennis later may have concluded, for
reasons that are unclear due to interruptions in his testimony, that the
throw may not have been used improperly. But he nevertheless main-
tained that the throw was the cause of the fire.

   Critically, Dennis did not recover any artifacts or samples from the
scene. Dennis testified that he had no reason to do so, nor did he
advise the Brytes to preserve the fire scene or any of its artifacts, for
the same reason: "I had no reason to believe it [the fire] was other
than accidental." Apparently no one, until his attorney did, instructed
David, Mrs. Bryte’s son, about preserving evidence from the fire
scene, and David removed the debris, including the recliner and elec-
trical devices, and disposed of it at a landfill that he owned.1

   Plaintiffs filed this suit about six weeks later, on December 1, 2000.2
In addition to Dennis, plaintiffs retained Dr. W.T. Cronenwett as an
expert witness to offer opinion testimony regarding the specific cause
of the fire. In his first deposition, Dr. Cronenwett opined that the elec-
tric throw was the ignition source of the fire. He based that opinion
on "[t]he absence of any other ignition source in the area, the snap-
ping and crackling that was heard, the fact that Mrs. Bryte was con-
fined to her chair, did not smoke and had no opportunity or means to
set herself on fire, and the fact that there are—have been a number
of instances where the Sunbeam electrically heated bedding products
have spontaneously burst into flames." More specifically, Dr. Cronen-
wett testified that the blanket caused the fire due to defectively
  1
    The magistrate judge credited Mr. Bryte’s explanation for disposing
of the debris, to which exception is not taken.
  2
    Plaintiffs settled with the other named defendant, Sears Roebuck &
Co., before trial.
6                 BRYTE v. AMERICAN HOUSEHOLD, INC.
designed circuitry. He acknowledged, however, that his opinion that
the defective circuitry in the throw had caused the fire rested wholly
on the conclusion of Dennis.3 Dr. Cronenwett attributed his inability
to independently identify the specific source of ignition to the fact
that there was "no remaining physical evidence" after the fire.

   Dr. Cronenwett was deposed twice, the second time in April 2003.
In addition to repeating his earlier questions, counsel for defendant
repeatedly asked Cronenwett whether he could identify evidence of
a malfunction in the electric throw that could reliably support his con-
clusion that the electric throw caused the fire. To each such question
with respect to various specific defects, Dr. Cronenwett acknowl-
edged that he could not, explaining, for example, that ". . . I never saw
any physical evidence of the blanket, so I don’t know what specific—
what the specific cause of the ignition was." Moreover, when asked
whether there was "any evidence in this case that can reliably support
a conclusion that there was any defect in any component part of the
electric throw that caused the fire in this case?" Dr. Cronenwett
responded "No." (JA 2019.)

   Prior to trial, defendant moved for summary judgment based on
failure of causation and plaintiffs’ spoliation of the physical evidence
of the fire. Defendant also moved to exclude the testimony of Dennis
and Dr. Cronenwett (and Messrs. Dallas and Hull) under Fed. R.
Evid. 702 and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509
U.S. 579 (1993), on the related ground that neither had a reliable basis
for his opinion that the electric throw or a defect therein had caused
the fire. In his Report and Recommendation, the magistrate judge rec-
ommended denying defendant’s motions, except as to Dallas, whose
opinion he deemed unreliable. Defendant objected to the Report and
Recommendation; the district court overruled those objections but
treated the motions as pending, took them under advisement, and
instructed the parties that it would rule on them at trial.
    3
    Dr. Cronenwett also relied on the investigation of David Dallas,
another cause-and-origin witness. The district court did not refer to either
Dallas’ or Hull’s testimony. We do not rely on either. Dallas did not tes-
tify at trial.
                 BRYTE v. AMERICAN HOUSEHOLD, INC.                     7
   The case was tried on December 8, 2003. At trial, plaintiffs
attempted to offer the expert testimony of Dennis and Dr. Cronenwett
in support of the claims that (1) the electric throw was the cause of
the fire, and (2) a design defect in the blanket was specifically respon-
sible for ignition. Contrary to the Report and Recommendation, the
district court considered plaintiffs’ proffers and determined that,
under Daubert, neither expert had a sufficiently reliable basis for his
opinion, and it thus excluded Dennis’ and Dr. Cronenwett’s testimony
as to causation. The district court also excluded plaintiffs’ evidence
about other, similar accidents and reports of defects. The district court
then concluded that plaintiffs had not introduced evidence sufficient
to permit a jury finding that the electric throw had caused the fire.
Therefore, at the conclusion of plaintiffs’ case the district court
granted defendant’s Rule 50(a)(1) motion for judgment as a matter of
law. This appeal followed.

                                   II.

  Plaintiffs assert five assignments of error:

    I.     THE TRIAL COURT FAILED TO PROPERLY
           APPLY THE "MALFUNCTION THEORY" OF CIR-
           CUMSTANTIAL EVIDENCE IN PRODUCTS LIA-
           BILITY CASES WHEN THE PRODUCT IS
           DESTROYED.

    II.    THE TRIAL COURT MISAPPLIED THE FLEXIBLE
           DAUBERT ANALYSIS OF RULE 702 TO
           EXCLUDE EXPERT TESTIMONY FROM MACK
           DENNIS AND DR. CRONENWETT BECAUSE
           THERE WAS NO TESTING.

    III.   UNDER THE "MALFUNCTION THEORY" OF CIR-
           CUMSTANTIAL EVIDENCE, OTHER RELEVANT
           EVIDENCE OF PRODUCT DEFECT AND SAFETY
           SHOULD HAVE BEEN ADMITTED.

    IV. EITHER WITH OR WITHOUT THE IMPROPERLY
        EXCLUDED EVIDENCE, THERE WAS SUFFI-
8                 BRYTE v. AMERICAN HOUSEHOLD, INC.
          CIENT CIRCUMSTANTIAL EVIDENCE TO SUB-
          MIT THE CASE TO THE JURY.

     V.   THE TRIAL COURT’S CONDUCT DURING TRIAL
          DEMONSTRATED BIAS, PREJUDGING OF THE
          CASE, AND OVERALL MEDDLING IN THE PRE-
          SENTATION OF EVIDENCE SO AS TO DEPRIVE
          PLAINTIFFS OF DUE PROCESS AND A FAIR
          TRIAL BEFORE AN IMPARTIAL TRIBUNAL.
          (Appellants’ Br. i, ii.)

   Appellate review of a district court’s interpretation or application
of state law is de novo. See James v. Circuit City Stores, Inc., 370
F.3d 417, 421-22 (4th Cir. 2004). Conversely, the district court has
broad latitude in ruling on the admissibility of evidence, including
expert opinion, and we will not overturn Daubert evidentiary rulings
with respect to relevance and reliability absent an abuse of discretion.
See Gen. Elec. Co. v. Joiner, 522 U.S. 136, 141-42 (1997). A district
court abuses its discretion if its conclusion is guided by erroneous
legal principles, or if it rests upon a clearly erroneous factual finding.
See Westberry v. Gislaved Gummi, A.B., 178 F.3d 257, 261 (4th Cir.
1999). Finally, we review de novo the district court’s grant of judg-
ment as a matter of law, see Freeman v. Case Corp., 118 F.3d 1011,
1014 (4th Cir. 1997), cert. denied, 522 U.S. 1069 (1998), considering
the evidence in the light most favorable to the non-moving party, see
Brown v. CSX Transp. Co., 18 F.3d 245, 248 (4th Cir. 1994).

   Taken together, we must determine whether the admissible evi-
dence, viewed most favorably to plaintiffs, would have allowed the
jury to render a verdict in their favor under West Virginia law.

                                   III.

   We first address assignments of error I and II which state plaintiffs’
principal claim on appeal, which is that the district court erred in
applying Daubert rather than substantive West Virginia law as to cau-
sation. In essence, plaintiffs rely on several West Virginia cases and
argue that, when a product allegedly causing a fire has been destroyed
by that fire, plaintiffs are allowed to rely on the "Malfunction Theory"
and circumstantial evidence to prove that a defect in that product
                  BRYTE v. AMERICAN HOUSEHOLD, INC.                     9
caused the fire. The argument goes that evidence as to causation is not
controlled by Daubert and the Federal Rules of Evidence, rather by
the substantive law of West Virginia which is claimed to embrace the
"Malfunction Theory" of proof of causation.

   Plaintiffs characterize the district court’s decisions on evidence as
reversible disregard for West Virginia law. The following colloquy at
trial succinctly illustrates plaintiffs’ argument and the district court’s
explanation for rejecting it:

     Plaintiffs’ attorney: "[T]he law in the Fourth Circuit and in
     West Virginia is that an expert need not review product
     remains to arrive at an opinion as to the probable defect in
     it."

     Court: "The evidence [law] is the Federal Rules of Evi-
     dence."

  As the transcript shows, plaintiffs essentially advocate applying
West Virginia law rather than the Federal Rules of Evidence where,
as here, products-liability claims, destruction of physical evidence,
causation, and expert testimony converge.

   The position of the district court was correct and has been decided
in Cavallo v. Star Enterprises, 100 F.3d 1150 (4th Cir. 1996). In that
case the district court, as here, entered a judgment for the defendant,
having excluded expert testimony as to the cause of the various
chronic illnesses of the plaintiff. The expert witnesses had offered tes-
timony that the plaintiff’s exposure to petroleum vapors from jet fuel
spilled or leaked by the defendant had caused the plaintiff’s illnesses,
upon which she sued. The court excluded the evidence because it was
not supported by appropriate validation, as required by Daubert v.
Merrell Dow, 509 U.S. 579 (1993). The position of the Cavallo plain-
tiffs in Virginia, similar to that taken here by the Bryte plaintiffs in
West Virginia, was that Virginia law should apply as to the admissi-
bility of the testimony:

     The Cavallos assert that, because their claims are grounded
     in Virginia state law and were originally filed in Virginia
10                BRYTE v. AMERICAN HOUSEHOLD, INC.
     state court, the admissibility of expert testimony should be
     governed by Virginia law.

However, we followed our decision in Scott v. Sears, Roebuck & Co.,
789 F.2d 1052 (4th Cir. 1986) and affirmed the district court, quoting
from Scott, 789 F.2d at 1054:

     Unlike evidentiary rules concerning burdens of proof or pre-
     sumptions, the admissibility of expert testimony in federal
     court sitting in the diversity jurisdiction is controlled by fed-
     eral law. State law, whatever it may be, is irrelevant.

100 F.3d 1150, 1157.

   This argument has been rejected by other Courts of Appeals in sim-
ilar cases dependent on expert testimony. For example, in Ealy v.
Richardson-Merrell, Inc., 897 F.2d 1159 (D.C. Cir. 1990), the defen-
dants appealed the district court’s denial of their motion for judgment
N.O.V. in a Bendectin birth-defects case. Plaintiffs defended the ver-
dict in their favor by arguing that Erie Railway Co. v. Tompkins, 304
U.S. 64, 78 (1938), required the district court to follow an earlier Dis-
trict of Columbia Court of Appeals decision that had affirmed a jury
verdict for different plaintiffs based on the "same four types of expert
data" relied upon by the federal plaintiffs. Ealy, 897 F.2d at 1163. The
D.C. Circuit agreed with defendants that reliance on state (decisional)
law was not required. Ealy, 897 F.2d at 1160 ("[t]he admissibility of
expert testimony [is] a procedural matter which does not implicate the
principles underlying Erie") (citation omitted). The court explained its
holding, that the district court abused its discretion in admitting unre-
liable expert testimony accepted by the state court, in terms applicable
to this case:

     Unfortunately for [plaintiffs], the only evidence they have
     on the issue of scientific causation is the testimony of their
     experts. Once that testimony is deemed inadmissible, it is
     self-evident that the evidence is insufficient to support a ver-
     dict for the plaintiffs. Contrary to the [plaintiffs’] assertions,
     however, this court is enforcing a procedural rule governing
     admissibility; it is not supplanting substantive state rules on
     the sufficiency of evidence.
                   BRYTE v. AMERICAN HOUSEHOLD, INC.                       11
Ealy, 897 F.2d at 1163; cf. Daubert v. Merrell-Dow Pharms., Inc., 43
F.3d 1311, 1322 (9th Cir. 1995) (affirming summary judgment for
defendants: "[p]laintiffs do not quantify this possibility [of causation],
or otherwise indicate how their conclusions should be weighted, even
though the substantive [state-law] legal standard has always required
proof of causation by a preponderance of the evidence"), on remand
from 509 U.S. 579 (1993). These decisions highlight the application
in the federal courts of the process that plaintiffs argue is a "misappli-
cation" of West Virginia law, rather we are of opinion that it is an
application of the rules of evidence under Daubert.

   Without significant exception, plaintiffs relied on Dennis’ testi-
mony to establish that the throw caused the fire.4 But Dennis did not
exclude all or even most of the other possible sources of the fire. As
set forth above, it is undisputed that Dennis did not physically exam-
ine the lamp, the candle, the cord that remained which he found on
Mrs. Bryte’s arm, or the wall outlet, or its wiring, which supplied
electricity to the throw. Moreover, he was unaware that an extension
cord was plugged into the same outlet as was the blanket, and there-
fore he obviously did not inspect it. These omissions are particularly
revealing in light of Mrs. Miller’s testimony that she could not unplug
the throw because she "would have gotten burned if [she] tried to pull
[the cord] out," which suggests fire on the left side of the chair near
the outlet, even if not in or on the outlet itself. It is clear that such pos-
sibilities have not been excluded in any methodical or reliable fash-
ion. And we are not obliged to credit Dennis’ say-so supporting his
own reliability by way of excluding other causes. See Kumho Tire Co.
v. Carmichael, 526 U.S. 137 at 157 (1999).

   Plaintiffs also assert that Dennis adequately excluded the most
likely alternative source of the fire, the candle, based on Mrs. Miller’s
observation that the candle was still lighted when she arrived at the
scene, as well as on the evidence that Mrs. Bryte could not reach the
  4
   As set forth above, Dr. Cronenwett was proffered to testify as to
defective electric circuits, not the fire’s origin. Dennis’ causation testi-
mony was an obligatory support for Dr. Cronenwett’s, as Cronenwett
acknowledged. Because we affirm the district court’s exclusion of Den-
nis’ opinion, we do not address in great detail the particulars of most of
Dr. Cronenwett’s testimony.
12               BRYTE v. AMERICAN HOUSEHOLD, INC.
candle. We do not think that Dennis’ explanation is sufficient to
explain away the candle. Our doubt arises not because of Dennis’ reli-
ance on Mrs. Miller’s observations, but because the fact that she saw
the lighted candle on the table in itself cannot exclude it as a cause
of the fire, rather the contrary inference is the more logical. This is
a matter of common sense: for example, the candle’s flame might
have burned the lamp shade above, as defendant suggested when
cross-examining Mrs. Miller, or either the blanket or the throw may
have been ignited upon contact with the candle which may have been
within reach of the decedent. Notably, though Mrs. Miller and Mrs.
Bryte’s daughter testified that the candle was out of Mrs. Bryte’s
reach, Dennis did not independently investigate why what appeared
to be the table’s remains were found close to the recliner, and his only
explanation for this was the implausible one that a fireman had kicked
the debris. The table with the candle on it was described by Dennis
as "immediately to your left of" the recliner, and a photo in evidence
shows the table as adjacent to the recliner.

   Daubert aims to prevent expert speculation, and our review of the
record convinces us that Dennis’ failure to independently evaluate the
open flame in the room cannot be reconciled with the reliability man-
date. Dennis was permitted to rely on what Mrs. Miller saw, but not
on her conclusions about the cause of the fire. As to the candle he
essentially did the latter.

   We also note that, at the beginning of the trial, the justifiable
impression of the district court, the depositions of most of the wit-
nesses having been taken, when Mrs. Miller left to get the child,
"there was a candle lighted on a table within reach of the decedent."

   Plaintiffs also argue that Dennis performed a methodical walk-
around inspection, which led him to the origin of the fire. Dennis’
investigation did indeed determine that the left side of Mrs. Bryte was
the "area of origin" for the fire—but he could not identify the "point
of origin." And, as seen above, Mrs. Miller testified as well that the
fire was on the outside of the chair, and on Mrs. Bryte’s left side as
well. Thus, though both Dennis’ "area of origin" finding and Mrs.
Miller’s testimony implicated the area where the outlet and the two
power cords were located, Dennis did not closely examine this area
and was unaware of a cord lying inches from the recliner, plugged in
                 BRYTE v. AMERICAN HOUSEHOLD, INC.                    13
to the same outlet as the throw. This is inconsistent with the NFPA
standards, which require investigators to exclude "[a]ll other reason-
able origins and causes." NFPA 921, § 2-3.6 (1999 ed.).

   Furthermore, Dennis’ causation testimony is called into question
by the fact that Dennis may have sought to explain his conclusion
about "improper use" of the throw, based upon the fact he "had infor-
mation that . . . [the throw] had been tucked down in beside the victim
in the chair and which I later learned the old style electric blankets
..."

   While the testimony of Dennis was cut short before he had
explained his use of the phrase "improper use" with respect to the
throw, the proffered testimony of Dr. Cronenwett with reference to
causation is instructive. The "snapping and crackling noises" referred
to throughout and referred to by Mrs. Miller are "characteristic of
burning . . . energized PTC cable" not the burning of an energized
power or service cord, for, "generally, when a service cord short-
circuits it explodes once and opens a circuit breaker. It would not con-
tinue to snap and crackle." Thus, "the burning of an energized service
cord for an appliance would be inconsistent with a snapping and
crackling sound described by Ms. Miller." Dr. Cronenwett had no
information that the circuit breaker was tripped in the line into which
the throw had been plugged. But because snapping and crackling
came from the burning PTC cable5, he logically excluded a burning
of the power cord to the throw as the cause of the fire. Apparently
unknown to Dr. Cronenwett, however, the circuit breaker, in the line
into which the throw was plugged, was tripped. When it was tripped
is not shown in the record. That it was tripped is shown by the testi-
mony of David Bryte, the son of the decedent: "[T]he breaker on that
particular circuit was tripped." With the power cord possibly removed
as the origin of the fire, and the burning of the PTC cable as the origin
of the snapping and cracking, it then is relevant to consider the testi-
mony of Dr. Cronenwett that "the PTC wire could also burn from
being attacked by an outside fire source as well." But does, or doesn’t,
the tripped circuit breaker make the various cords (or their appliances)
plugged into the circuit, candidates for the origin of the fire.
  5
   A PTC cable is the cable containing the heating element and runs
throughout the throw.
14                 BRYTE v. AMERICAN HOUSEHOLD, INC.
   All of these reasons serve to support the decision of the district
court in excluding the causation testimony of Dennis, and we are of
opinion the district court did not abuse its discretion in excluding that
testimony. It described the record at this point as "so speculative that
a jury has to guess to determine whether there is liability of either the
warranty or negligence for the jury to speculate on."

                                   IV.

   In the third assignment of error, plaintiffs challenge the district
court’s exclusion of other evidence such as "other accidents including
the same product." Here, too, we find no abuse of discretion. See
Westberry, 178 F.3d at 261.

  Plaintiffs rely largely on this court’s decision in Riley v. De’Longhi
Corp., No. 99-2305 (4th Cir. Oct. 30, 2000), in support of their argu-
ment regarding other relevant evidence.6 In Riley, we determined that
four of the five factors applicable to analyzing the sufficiency of evi-
dence of a product defect under Maryland law favored reversing sum-
mary judgment for the defendants.

   Under Riley, the rule in Maryland in deciding whether there is suf-
ficient circumstantial evidence of a product defect to proceed to trial,
is that the court considers five factors: (1) expert testimony as to pos-
sible causes; (2) the occurrence of the accident a short time after sale;
(3) same accidents in similar products; (4) the elimination of other
causes of the accident; and (5) the type of accident which does not
happen without a defect.

     As to each factor:

  (1) The testimony of Dennis, that the fire originated in the throw,
was inadmissible, so there was no expert testimony as to the possible
cause.
  6
   Our mention of Riley is no indication that we rely on it as binding cir-
cuit precedent. See Fourth Circuit Local Rule 36(c); Hogan v. Carter, 85
F.3d 1113, 1118 (4th Cir. 1996) (en banc).
                 BRYTE v. AMERICAN HOUSEHOLD, INC.                    15
   (2) The fire in this case occurred some two years after the sale, so
there might be a question of fact as to whether the accident occurred
a short time after sale.

   (3) As the district court correctly held, there was no proof that the
facts in this case were the same or similar to what transpired in the
other cases, so there was no showing of the same accident in similar
products.

   (4) In this case the elimination of other causes of the accident has
not been shown, as we have related above, so there has been no show-
ing of the elimination of other causes of the accident.

  (5) Since there is no showing of the cause of the accident, there
has been no showing of a type of accident which does not happen
without a defect. Thus, even under Riley, the evidence of "other acci-
dents involving the same product" is not admissible, only one factor
possibly being favorable.

   A general logical fallacy similar to that mentioned just above
undermines plaintiffs’ theory that the district court was required to
admit evidence of substantially similar incidents and reports implicat-
ing a Sunbeam throw. That is, plaintiffs sought to introduce such evi-
dence without establishing their premise: the salient characteristics of
this incident, as well as of the incident to which comparison is sought.
The district court commented:

    And I agree with [plaintiffs’ counsel] one hundred percent
    [that it is proper to bring evidence of other similar inci-
    dents]; and once you get a witness who testifies that this is
    similar to what went on in these other cases, I might let it
    come in . . . .

   We are of opinion that the district court did not abuse its discretion
in denial of evidence of "other accidents involving the same product."

                                   V.

  The fourth issue is plaintiffs’ argument that "with or without the
improperly excluded evidence, there was sufficient circumstantial evi-
16                 BRYTE v. AMERICAN HOUSEHOLD, INC.
dence to submit the case to the jury." We review de novo the district
court’s grant of judgment as a matter of law. See Freeman v. Case
Corp., 118 F.3d at 1011, 1014 (4th Cir. 1997). Though we consider
the evidence in the light most favorable to the non-moving party,
Freeman, 118 F.3d at 1014, given our affirmance of the district
court’s decisions as to the admissibility of evidence, the required
result is judgment for the defendant. With no witness as to ignition,
there simply was no evidence of causation other than Dennis,’ and via
that, Dr. Cronenwett’s, testimony. As in Ealy, "the only evidence
[plaintiffs] have on the issue of scientific causation is the testimony
of their experts. Once that testimony is deemed inadmissible, it is
self-evident that the evidence is insufficient to support a verdict for
the plaintiffs." 897 F.2d at 1163 (emphasis added). We are of that
same opinion here and so hold.

     The judgment of the district court is accordingly

                                                            AFFIRMED.7
  7
    We have also considered the plaintiffs’ argument that the trial judge’s
"conduct during trial" demonstrated bias, prejudging of the case, and
overall meddling in the presentation of evidence so as to deprive plain-
tiffs of due process and a fair trial. We have examined the record and are
of opinion that the argument is without merit, and we so hold.
