Mahomes had an opportunity to run out of bounds. As soon as he turned back in field then the defenders have to be able to go and tackle him. What are they meant to do? Run out of the way and allow a first down?I know what you mean but what are you going to do? Permit QB's to get blasted? Its quite clear that QB's are a lot more mobile and rely on their legs much more than in the past, where do you draw the line?
It's ok for Aikman to shout about too much protection but he was a completely static operator who rarely if ever crossed the LOS. What does he know about the modern QB.
Mahomes ran up to them and slides right at the last second. They are already fully committed to a tackle and ended up hitting each other as much as Mahomes. It just cannot be a penalty or the game will be ruined. Either run out of bounds or expect to be tackled - it shouldn't be that complicated to officiate.