I read these replies earlier and they have been very helpful. Sincerely, ty to everyone who replied. Lots of useful info.
To clarify a few things, I did not assume that they covered damage to car seats. I had previously actually assumed the opposite; that their liability would be pretty meager. In this incident tho I went by what the UA phone agent said (he did not say they didn't cover it but instead in summary said bring it in, let them look at it, we'll sort it out) and this web page that I Googled that rather hectic night:
http://www.united.com/web/en-US/cont...ge/infant.aspx
Which only specifically mentions not covering damage to strollers. I have now been educated and again ty for the info.
The situation appears to have been resolved in a fashion similar to harryhood's experience; the supervisor finally got back to us and offered a $100 United voucher. And no, I have no status with United.
Am I satisfied? No, United took our nice car seat (that was a gift from the inlaws, they are disappointed) and ran over it and destroyed it and left us at the airport environs with no safe way to transport our child. If there had only been one of us traveling with him I guess he'd have been driven to find a new car seat in the completely broken car seat. So yeah, I guess a $100 is more than they might have to offer but it's far from satisfying.
Definitely learned more than a few lessons.