There is no reason to believe
I think there are more than enough reasons to be suspicious about it.
Like it have been said earlier, that kind of move in the regular asset market would lead you to an investigation by the SEC
But the point he (appears) to be wanting to make is that there is too much speculation in crypto and he would have to be a complete corrupt asshole to speculate on this. It might have been irresponsible but a this point it's an unfounded conspiracy theory that he did this.