Idk, the way he leaned back a little, kinda looked like the beginning of a slide, intentionally or not.
Regardless it is absolutely true that defenders are scared to hit or tackle anyone. If they hit someone on the sideline it’s a penalty, even if they are in bounds. Later in this game, Allen got a call for being hit on his slide. He slide late and the defender pulled off as best he could in that situation, and it’s still a penalty.
Basically the defender is left to assume there’s a slide coming or assume the qb will just run out of bounds. If they react with a tackle, it’s called a penalty almost every time. Mahomes does the fake “I’m headed out of bounds” all the time and draws flags when he is still in bounds all the time.