Why was Banesto's Gonzales Arrieta kicked out of the Vuelta in 1995?

Explanation

During Vuelta a España 1995, Gonzales Arrieta (Spain, Banesto) and Leonardo Sierra (Venezuela, Carrera Jeans) created a stirr when they started fighting in the middle of one of the stages. After a few kicks and punches had been shared beteeen the two, they were both kicked out of the race.