I've never intentionally been rude to a CM, my dad has worked in the restaurant business for years, so I've had that instilled in me practically since birth. I, did, however, snap on a girl my age taking flash pictures in Spaceship Earth. It wasn't just one or two, it was literally every time the scene switched. I have about zero tolerance for flash photography on a dark ride and I very loudly said "Maybe this ride would actually be fun if someone stopped taking flash pictures." The girl did stop, but honestly I didn't feel bad about it.
One time at Haunted Mansion, my father and I were separated after exiting the stretching room and entering the ride loading area. A rather large party had squeezed their way in between us. Now, my father and I aren't people who need to be together 100% of the time, so we were okay riding alone. However, another gentleman with his family, who were in front of the larger party, noticed us talking to each other and asked if I would like to step in front of him, so I could be with my dad, which, I accepted. The large party behind us, one gentleman in particular, was clearly upset about that, as they kept making snide comments throughout the entire ride loading process. Finally, my dad, who is typically pretty level-headed when dealing with the public, made a comment about the university he attended (he was wearing an alum shirt and it was a university that's close by and does not have a good reputation around here.) It was mean, but it shut him up.
However, besides those two incidents, we're both pretty cheery at WDW.