Replaced A/C compressor, now car won't start


The subject line about covers it, but here's the backstory. The clutch on the A/C compressor locked up. I disconnected the pressure switch so i wouldn't accidently turn the A/C on while driving (not that I would, but just to be careful) and drove the car fine for a couple of weeks (good mechanics around here are booked out a couple of weeks). Took it to the mechanic and he disconnected the battery then removed the compressor and replaced it, reconnected the battery, then went to start it up to recharge the system and it wouldn't start. I'm not at the shop, as the shop is now closed and I just got his voice mail. Does anything come to mind? Like, could he have bumped and disconnected or broken a sensor? I've used this shop many times before and they are honest, competent and friendly--in fact, my daughter's neighbors. They have an excellent reputation. So I know they're not trying to scam me. I need to have the car running before Saturday. I've printed out the no-start article from here, but thought I'd see if anybody had any ideas.
^^^^ this is one possible issue.

Did he disconnect and forget to reconnect the orange wire running from the battery to the ECM? Or pop the fuse?