Cook's memo says that the reports, from the bureau as well as from the app's users, are "credible." That at least implies that Apple evaluated the credibility of the claims. I do understand that some people (like Gruber) might want Apple to provide material evidence, but is that really Apple's responsibility or usual behavior? It would seem extremely odd (and not at all comforting) to me if Apple, for example, released video evidence of a violent attack along with some record of this app being used by the attacker. That seems like something a government should do in a legal case, of course, but it would be seem strange to me for Apple to do that. And even if they did, I suspect it wouldn't convince people who are convinced that China is doctoring or inventing evidence to vilify the Hong Kong protesters.