You're not alone, I did a similar thing with a Cali 1400. I removed the lock mechanism from the side panel so could remove the panel from the bike altogether. When I replaced it, I forgot to refit the lock, and I didn't realize it until I had slapped the seat back on!
Of course the side panel could not be removed because the seat was hiding the two upper screws, and the lock was somewhere behind the panel. Somehow I managed to find the cable and pull on it to open the seat. I'm more careful now (yeah, right!).