Normally in disputes I find myself to be on the buyer side ... but for this one I think its clear you're on the right.

The fact that the buyer can't do such a simple thing as prove what he is saying shows that his behaviour is highly suspect.

Looking at the video that he sent you, it looks super fake. He looks like he's tapping instead of actually pressing the button.
Also no proof that its the actual console that you sold him.

So he's either:
1) Too stupid to follow very simple instructions like clearly pressing a button and showing a serial number.
2) He's lying.

There's a very easy way for my opinion to completely shift in his favour though, he just has to send a proper video to prove what he says is true.
But that doesn't mean I will no longer think he's stupid.

At this point I think myself and the other neutral person who commented here no longer care about the 'he says - she says' kind of argument.

We're judging what we can see with our eyes and what makes logical sense to us, and on both counts it doesn't look good for you bro.

More so now that you didn't respond to the questions we raised in our comments and went on a tangent to attack the seller.