in my 20 year of officiating I have had one intentional pass interference call, receiver ran a out and up, the corner bit on the out and fell down the Split end was wide open on the up the QB underthrew the Split End causing him to stop and come back for the ball which gave to corner enough time to gather him self and with out even looking at the ball nailed the receiver before the ball got to him, this was in the day before defenseless players, the PI was obvious what made it intentional in my eye was I could hear the corner back yell no way you are catching the pass
it was on b's sideline coach told me good call