The only time I've seen people complaing about not calling an obvious shot is in some leagues and against a very few specific players in tournaments. Every tournament I play in, as well as in my local USAPL league, if it's called shot, even if it's a bank or a clear combination, if it's not called, it is assumed it was by 95% of the people.
Even if someone kicks at a ball without calling it, but it's clear that was the pocket is should go in if you were calling it, I would not say anything. And I have seen most players do that as well, including my son who I made sure is not one of those asshats that yells if you happen to nudge a ball on the way to a pocket about you not calling a "combo" or something silly.
I've had one guy ***** at me because there were 3 balls near each other and I shot one in without saying anything. Like he really thought I totally missed the ball I was trying to shoot and accidentally hit the ball 2 inches from it and made that by accident. Told me all I needed to know about him.
Funny part is that it's usually the guys that try to get away with fouls and not calling shots themselves that are the most vocal about complaing about others.
Unless you are playing a combo carom bank, if it's against me and I know that you know that I know that you knew where the ball is going, it's all good.