Holyfield is notorious for using his head. I heard an announcer joke once that there should be a glove on holyfield's head.

He butted Tyson the first fight as well.

It was definitely not innocent. He knew what he was doing. I honestly think it was part of his gameplan before the fight to head butt tyson.

Tyson was a prime target because at that stage in his career he would just try to rush inside. Holyfield would plant his feet and put his head down. He was using his head from the opening bell..he knew what he was doing.