Creating hypothetical situations now? The defender being there to rip the ball out after he was already down, by contact, with the catch secured, is the reason we are having this discussion. If there’s no defender, it remains what it should have been in the first place. A catch.
One way to think about this I’m sure has been said but I haven’t seen…
If there were no defender at all and Cooks just lost possession of the ball on his own (at the same time he did in the actual play), would it matter he controlled the ball while his knee/body was down?
No, it would be clearly incomplete as he didn’t maintain possession through the entire act.
The defender taking the ball acts the same as Cooks losing possession on his own in this case.