AP Arrow

[bisonpitcher]

In a recent MS game, I was administering a AP throw in from the endline. Team A had possession by the arrow. Team B is pressing. A attempts to inbound and ball goes out of bounds on sideline without being touched by either team. I give B possession at the same spot as A's throw in. My partner is T, table side. After B inbounds the ball, I notice that the arrow stayed with A. As I'm going down court past the table next time down, I motion for them to switch the arrow. They looked at me dumbfounded. At the next break in action, I went to the table and asked them to change the arrow to B. The timer said that my partner told them at the time not to switch the arrow. I ask my partner, who says that the arrow doesn't switch because no one touched the ball inbounds. I said that is a throw in violation on A, and therefore ends the throw in, which means the arrow switches. He was adamant, and was the R for this game, and is more experienced than me; so I didn't press the issue (the game was not close and no one was complaining about the arrow). I still think I was right. I couldn't find a case in the book, but to me 9-2-2 seems to back me up. Opinions?? Also is there any instance where the arrow will not switch, other than fouls prior to the throw in is complete?