Gorsuch, J., dissenting
sion that the strong would have been adverse”); Clifton v. United States, 4 How. 242, 248 (1846) (the withholding of “more direct” proof suggests that “if the more perfect exposition had been given it would have laid open deficiencies and objections which the more obscure and uncertain testimony was intended to conceal”); 31A C. J. S., Evidence §156(2), p. 402 (1964) (“The unfavorable inference… is especially applicable where the party withholding the evidence has had notice or has been ordered to produce it”). Meanwhile, a similar inference may not arise if no one’s bothered to ask for the evidence, or if the evidence is shown to be unavailable for a good reason. In cases like those, there may be just too many other plausible and innocent excuses for the evidence’s absence. Maybe, for example, nobody bothered to seek the underlying data because everyone knew what it would show.
Fine, the Court responds, all that’s true enough. But even if we accept that an expert’s failure to produce the evidence underlying her conclusion may support an inference that her conclusion is unsupported, that doesn’t mean such an inference must follow. Whether an inference is appropriate depends on the facts of the particular case. See ante, at 9–10.
But what more do we need to know about the facts of this case? All of the relevant facts are undisputed, and it remains only to decide the legal question whether they meet the substantial evidence standard. We know that the expert offered a firm and exact conclusion about the number of available jobs. We know that the expert claimed to have private information to support her conclusion. We know Mr. Biestek requested that information and we have no reason to think any confidentiality concerns could not have been addressed. We know, too, that the hearing examiner had “no other reason to trust the expert[’s]” numbers beyond her say-so. Ibid. Finally and looking to the law, we know that a witness’s bare conclu-