Wow, I haven't competed yet, but I see no excuse for this. I know when I start competing if I see/hear this I'd be very put off.
Now don't get me wrong, a little fun natured ribbing and trash talk among friends can be fun, it's not appropriate for people you don't know and at competitors who are out there to have fun, learn, etc.
So like you, I'm interested in hearing what others say, as I hope this isn't common. As for you, did you discuss it with the people running the meet or the two who acted that way?