To Bonehead is to perform an act like jumping up and down, talking on a cell phone and holding up a sign behind a live television show, usually behind a news reporter doing a newscast.
The bonehead was doing a funny sort of dance behind the news reporter for attention and for a few seconds of television stardom.
A racist or neonazi with a shaved head that people often confuse with skinheads. Boneheads are racist and copied the style of the original skinheads, which were and are a non-racist subculture with shaved heads. Boneheads and skinheads do not get along and are at natural odds with eachother; enemies.
The boneheads just got kicked out of the oi show by the skinheads, because racism is not allowed at skinhead shows.