A couple things to take into account.
1. He was white. White people always do stupid stuff like this to impress their friends.
2. He was overweight. The ancient Romans used to keep their gladiators a little on the hefty side because fat is like +1 armor.
3. He was naked. No clothing to catch on the machinery.
4. He laughed maniacally. Some would call that a crazy person laugh and as well all know crazy people never seem to get hurt when you want them to.
