Alright. Let's look at the timeline.
First event. Chapter 988. King crashes Sanji into the tower saying that he will split him open. (fan translations here. I don't have access to the official ones right now). Luffy hypes the attack (the official translation is a little different, but still has the same meaning). So we can say that it WAS a strong attack. A full speed crash hurts. "speed is weight" or something was something Kizaru said back in Sabaody. And Physics also explains it.
Second event: Chapter 989. King appears but the beak is seen from an "above" perspective. Not possible to say if it's bent here or not.
Third event: Sanji gets up still in one piece, talking about the durability of the Raid Suit.
Event 4: King's beak has its tip offpanel. Again, we can't say whether it's bent or not.
Event 5: Chapter 990. King reverts back to "human form", so we have to skip until he reverts back to Zoan Form, while looking for any kind of event that could bend his nose during this time.
Event 6: Chapter 999. King's back to Zoan Form. There wasn't a single moment when he was attacked during his human form before this scene. His beak is clearly bent.
Event 7: Beak still bent. Even MORE clearly.
So there we have it. There was NOTHING aside from the crash that could have caused it.