Instead of one mistake, it becomes a cluster**** by depriving Team A of the ball, giving Team B the ball, AND making Team B use its arrow.
I don't understand what your R is saying. By not changing the call with the additional information, all he's done is add more "egg" to yours and the entire crew's face. With his line of thinking, he wouldn't want you to change an out of bounds call if he clearly had information that was contrary to your call.
If I was in your situation, as soon as my partner(s) give me that information, I'm blowing my whistle and changing the call.
Me: "Jump ball...Team B's ball"
P: "We've got two Team A players with the ball."
Me: "You're right..." *Tweet* A's ball
Doing it quickly like that wouldn't give this R a chance to change the call since he's all about "egg" on people's face and I'm assuming he wouldn't want any on his face.