State v. Thornley

686 November 12, 2026 No. 1101 This is a nonprecedential memorandum opinion pursuant to ORAP 10.30 and may not be cited except as provided in ORAP 10.30(1). IN THE COURT OF APPEALS OF THE STATE OF OREGON STATE OF OREGON, Plaintiff-Respondent, v. EMILY THORNLEY, Defendant-Appellant. Washington County Circuit Court 22CR41464; A184499 Andrew Erwin, Judge. Argued and submitted October 7, 2026. Joshua B. Crowther, Deputy Public Defender, argued the cause for appellant. Also on the briefs was Ernest G. Lannet, Chief Defender, Criminal Appellate Section, Oregon Public Defense Commission. Derek Olson, Assistant Attorney General, argued the cause for respondent. On the brief were Dan Rayfield, Attorney General, Paul L. Smith, Solicitor General, and Erin K. Galli, Assistant Attorney General. Before Tookey, Presiding Judge, Egan, Judge, and Jacquot, Judge. TOOKEY, P. J. Reversed and remanded. Nonprecedential Memo Op: 354 Or App 686 (2026) 687 TOOKEY, P. J. Defendant appeals a judgment of conviction for one count of driving under the influence of intoxicants (DUII), ORS 813.010. In two assignments of error, defendant con- tends that the trial court erred by “excluding the defense witness[’s] expert opinion that defendant was experiencing withdrawal from [b]enzodiazepine at the time of her arrest.” We reverse and remand.1 First, we conclude that defendant’s assignments of error were preserved. “Preservation gives a trial court the chance to consider and rule on a contention, thereby possibly avoiding an error altogether or correcting one already made, which in turn may obviate the need for an appeal.” Peeples v. Lampert, 345 Or 209, 219, 191 P3d 637 (2008). “Preservation also ensures fairness to an opposing party” and “fosters full development of the record * * *.” Id. at 219-20. “Ultimately, the preservation rule is a practical one, and close calls * * * inevitably will turn on whether, given the particular record of a case, the court concludes that the policies underlying the rule have been sufficiently served.” State v. Parkins, 346 Or 333, 341, 211 P3d 262 (2009). Error assigned to the trial court’s exclusion of evidence generally requires an “offer of proof of the excluded evidence” that “adequately inform[s] the trial court of the nature of the evidence at issue.” State v. Smith, 309 Or App 268, 279, 482 P3d 174 (2021). In this case, the trial court was adequately informed that defendant sought to introduce expert testimony diag- nosing her with benzodiazepine withdrawal, and the trial court had the opportunity to contemplate whether such tes- timony was admissible. In defense counsel’s opening state- ment, defendant indicated that her expert would testify that she “was not, in fact, impaired by cannabis, but rather [experiencing] another medical phenomenon” at the time of her arrest. During defendant’s examination of the defense expert, defense counsel asked whether the expert had 1 On appeal, the state concedes that the “trial court erred in excluding [the defense expert’s] diagnosis regarding benzodiazepine withdrawal” and argues only that defendant’s assignments of error were either unpreserved or harmless. We accept the state’s concession and limit our discussion to preservation and harmlessness. 688 State v. Thornley “reached any medical conclusions about [defendant’s] condi- tion at the time she was arrested,” resulting in the expert’s testimony diagnosing defendant with benzodiazepine with- drawal. The state objected to that testimony and an OEC 104 evidentiary hearing regarding the admissibility of the diagnosis followed. During that hearing, the trial court had the chance to consider and rule on the admissibility of the diagnosis, and did so, stating, “I’m not going to allow a diag- nosis of the withdrawal at [this] moment in time.” Other policies underlying preservation—includ- ing, “fairness to an opposing party” and “full development of the record”—were also sufficiently served for the same reasons stated above and because the state and trial court had the opportunity to examine the expert witness about his diagnosis of defendant during the OEC 104 hearing. Accordingly, we conclude that defendant’s assignments of error were preserved. Second, we conclude that the exclusion of expert testimony diagnosing defendant with benzodiazepine with- drawal was not harmless. In determining harmlessness, “the question is whether, after we review the record, we can say that there was little likelihood that the erroneous exclusion of the witness statements affected the jury’s verdict.” State v. Davis, 336 Or 19, 32, 77 P3d 1111 (2003). “If erroneously admitted or excluded evidence relates to a central factual issue in the case, it is more likely to have affected the jury’s determination than if it deals with a tangential issue.” State v. Johnson, 225 Or App 545, 550, 202 P3d 225 (2009) (inter- nal quotation marks omitted). The “exclusion [of evidence] may be harmless if it is merely cumulative of, instead of qualitatively different than, evidence presented to the fact- finder. State v. Bement, 363 Or 760, 779, 429 P3d 715 (2018) (internal quotation marks omitted). Because the “potential for scientifically based evidence to exert influence on a jury is manifest,” the “erroneous exclusion of scientifically based testimony of an expert witness” ordinarily “weighs against a determination that the error was harmless.” Johnson, 225 Or App at 555 (citations omitted). In this case, we cannot conclude that the exclusion of the above-described expert testimony “had little likelihood Nonprecedential Memo Op: 354 Or App 686 (2026) 689 of affecting the verdict.” State v. Bowman, 373 Or 213, 232, 564 P3d 121 (2025) (citation omitted). Whether defendant was experiencing benzodiazepine withdrawal or intoxica- tion from cannabis (or both) at the time of her arrest were central factual issues in the case. Additionally, our review of the record does not indicate that the defense expert’s diagnosis was cumulative of other evidence in the record. Evidence that “defendant displayed some of [the] symptoms” of benzodiazepine withdrawal at the time of her arrest was “qualitatively different” than an actual diagnosis. Indeed, a diagnosis from a credentialed expert has an “aura of reli- ability” not attributable to general testimony about symp- toms of a medical condition. State v. Southard, 347 Or 127, 140-41, 218 P3d 104 (2009). This is not a case where excluded medical testimony “would merely have reiterated what was uncontroverted.” Sanderson v. Mark, 155 Or App 166, 180, 962 P2d 786 (1998). Rather, “scientifically based evidence” of defendant’s diagnosis, which was in contention and had the “manifest” potential to “exert influence on [the] jury,” was excluded from the jury’s consideration. Johnson, 225 Or App at 555. Therefore, we conclude that the exclusion of the expert witness’s testimony diagnosing defendant with ben- zodiazepine withdrawal was not harmless. Reversed and remanded.