Not at all. Its a race and everyone is shooting for the best time, so you can't expect them to pull over. Its fine to squeeze around them to pass. Nobody ever seems to know their swim time within 10 seconds. Even if you are spot on, the people around you won't be. Make your best guess and deal with the carnage later. Most people give themselves a time faster than they really are. People near the front of the pack are more likely to have accurate times (but there's always a REALLY slow person who out of ignorance gives themselves a ridiculously fast time). People near the back of the pack are more likely to stop and let someone pass at the wall. Just my observations - you are perfectly within your rights to barge around people.

Pool swims are usually like that...there are a lot of bikers who can't swim to save their lives, but don't want to be too far back heading into the bike leg, so they imbellish their time a bit. Plus there are those people who are really just out of touch with reality and think they are much faster than they are. I usually post my expected time about 1min faster than I think I'll do and I still pass more people than pass me.

Now you know what's really a mess, a pool swim with a first come first serve (ordered by what time you sign up) pool swim start. There's not even an attempt at order. I do this sprint in the St. Louis area every year, it's a fun race but does the first come first serve start. The good thing is if you sign up late, you get plenty of people to pass, and you can watch the swimming from the stands. It's non-USAT (not suprisingly), so you get to see some interesting stuff like a person using a snorkel to complete a 500yd pool swim

Maybe it is, I just would have guessed not...not that it would give you a competitive edge

That would solve my breathing problems :-)

Thanks, it's good to know that I wasn't doing anything unexpected. I wasn't watching the people ahead of me closely enough to see what the action was ahead of me.
It was only 40 degrees outside so I was hopping around trying to keep warm get the HR up. Pool was a toasty 82 degrees, my feet felt like they caught fire when they hit the water.