The most epic of my chokes probably was on icfp contest of 2007. Plenty of pressure, tight deadlines (icfp contests take 72 hours). There was a hard to reproduce bug in my fast dna vm implementation, and it took me like 18 hours to find that one wrong line. I think "stuck in debugging" usually means choke.

As for panic, that's more of a sysadmin thing, imo. When a RAID fails to come back after a power failure on the production server, it does take some guts to not start making random stupid moves.