I think the ball went out pretty quickly and then it stopped for a VAR check.
Incidentally, and just to sum up the FA on this, I just went to their official Youtube channel to check the highlights of the final, and this complete red card cock up wasn't considered important enough to include in their highlights video. Funny that. Nor did it appear in their 'key moments' video. So it turns out us, every pundit and all of the media are just kidding ourselves. It was just a minor moment that had no impact on the game whatsoever.
Burying the evidence of their incompetence.
ETA: Actually, the City channel shows the full play. They clear it and I'd guess (because it's cut) that it just goes to VAR at the next stoppage.
Hell, even the Palace Youtube channel shows it. But the FA too cowardly as usual.