If I'm very sure my ball is out, but my opponent just doesn't call it, I'll volunteer that information. I need to be really sure though, and the situation doesn't come up that often because for me to be really sure, it's pretty much got to be obvious to my opponent(s) too, unless something out of the ordinary was going on, like they just didn't even have their head turned the right direction. If I just think 'hey that was probably out' but they don't call it, well it's their call and I could be wrong so I just don't worry about it and keep playing (or take the point if they don't get it back).
Also think getting upset at something like this (the opponent saying something about a close ball but then accepting your call) is kinda silly and not at all productive, you should probably work on not letting trivial things like that get to you. It's not even that uncommon, but I never expect the opponent to actually overrule me and call their own ball out, as they have no obligation whatsoever to do so, it isn't their call. Just say something like 'I wasn't sure so I called it in' and move on to the next point.
Last edited by dcdoorknob; 12-21-2012 at 03:45 PM.