There's no maybe about it, it wouldn't have. Duffy was our deepest defender when Murray was fouled, he only came up because the corner had been given (and he's supposed to come up for corners, not penalties).
If he took out Izzy first, then it should have been a penalty. I haven't noticed that yet.
EDIT - I've got 3 angles here, and I think he gets the ball at least as early as colliding with Izzy.
Obviously as others have said, getting the ball doesn't instantly make it no foul, it still can be...