
Are you joking? They're painfully obvious and only become more stark on replay. It's nothing to do with "landing on the toe pick" (everybody lands on the toepick otherwise you're gonna have a bad time). He's not rotating. Plain and simple.
My view, though I don't claim to be an expert in the coaching department, is that maybe it would be better to take a huge step back. Stop doing quads for a while - or pick one he can actually get called around in competition and just work with one. Get the triples nice and big and clean, and one, or two quads called clean - even take it back to the toe and Salchow. Do that for a while, build up some nice goodwill for consistency and also start stacking up the clean protocols.
Then, and only then, start re-introducing the harder quads. Yes, it will take time, but this is the perfect time to do it! We're at the beginning of the quad, it's still four years til the next Olympics, and Vincent's only
just turned 18.