This is a pretty detailed break down of what happen.
http://www.scout.com/college/ucla/story/1557549-details-of-p-diddy-s-arrest-at-ucla
http://www.scout.com/college/ucla/story/1557549-details-of-p-diddy-s-arrest-at-ucla
In the next moment, according to many on the scene, Diddy attacked Alosi, until interns and other personnel pulled off Diddy. The celebrity broke free again at one point and struck Alosi. The personnel were then successful in getting Diddy out of the office and into the weight room, where Diddy picked up a kettlebell, which is a type of barbell, and then swung in at one of the interns.