you could see the moment where he though "oh hey I'm hanging in the air above the keeper, I suppose if I dropped my legs on him I could win a peno here"
To be fair, Zieler was nowhere near the ball. I often find with this "diving" that the fouler either blocks them off, misses the ball completely or both.
Good peno, what a game
But those situations it's always tough, if he doesn't jump over the keeper be risks getting his foot stuck under him and maybe getting injured but it'd be a pen. Jumping over him, the keeper clearly puts him off and makes him lose the ball