I would rather I catch the AR's flag up and not have the coach or spectators tell me to look at my AR. But, as long as I see the flag, even after someone on the sideline yells, I am okay with it. I have had AR's, usually inexperienced AR's, that were slow to put a flag up. I looked at them before their brain had a chance to tell their arm to raise. It will only happen once per game and I realize the AR is slow, so I will look at them more often especially if play is going away from the AR and into a corner.
I get pissed off at myself when I miss a flag. If it is my AR screwing up the mechanics then we have a talk at halftime to help educate the AR.
Yes, go ahead and help out the referee but do it in a polite manner. "He ref are you blind? The AR has their flag up." Will normally cause a conversation between the ref and the coach that may get you sent to the parking lot.