I've always thought the canvas looks brutally hard compare to a wrestling mat and wondered how guys adjust to wrestling on a harder surface, let along what it feels like to get slammed on it. It seems like a pretty good way to ruin someone's night in a moment. When Tito ko'd Tanner he had a bodylock and his head tucked against Tanners chin so when they hit the ground his head took a huge impact. Or like when Harris Ko'd branch with a slam, Branch had jumped to guard and Harris put his hand up on his face, then slammed him with a Ko. Also the Khalibov slam he has a body lock from behind with his opponents arm trapped in it and slams him with no way to protect his head as he went down. My point is, especially with the tito and khalibov examples, I don't think there is anything that their opponents could do to stop them from getting ko'd with those slams. Yes, they could have avoided the position, but we see guys in those positions all the time but they rarely even attempt those kind of slams. Final thought, it seems that there is a grey area with head butts in relation to slams, not sure if it will even be changed, but I'm curious why we don't see more slams with intent to end fights. My answer is most likely fighters trying to conserve their gas and the fact that if you did that to your training partner you would probably get kicked from your gym lol.