You do know how easy it is to go into developer mode, inspect element, and make things say whatever you want to say, right? How do you prove that was not done?
Occam's razor: that dude started back in May to provide data and screenshots, I don't see feasible that somebody faked data for so long hoping to achieve what?
I'm not sure you can really argue occam's razor is that this guy just makes incredible bets on stocks. Surely the simplest answer is: People on the internet lie.
I'm not saying I feel strongly either way, but I think peopel on the internet lying is a pretty simple explanation.
It would be just as easy for DFV to create a second account and run a different strategy on that. Since DFV wasn't the instigator for the short-squeeze mania I am kind of hoping that he did.