Asking a question when your not involved in the pot...

[PokerDork]

First of all, I would say that normally I would just let the dealer handle this kind of matter. But, this dealer was somewhat inexperienced, and I had some reason to suspect that Player A may have been shooting an angle. Anyway, at the river, Player A checked, Player B bet, and player A with chips in his hand Move them over the line on the table, after holding them above the felt he then motioned to fold. I then asked the dealer if he had to call. The dealer said "No", but Player A had not mucked his hand yet- he then called. Player B who had TPTK, was angry with me for asking a question about a pot that I wasn't involved with. I apologized (even though his TPTK was solid gold if his opponent had any thoughts of folding), but I felt given the situation- newish dealer, and likely angle shooter, that my question was asked in the spirit of maintaining a fair game. Thoughts?