Hey Aarik,
I'm not 100% on exactly what I did in between hiring the new adventurer and noticing the missing shields... It wasn't more than 30 mins later I noticed that they had disappeared.. I believe I initially tried to just equip that really nice grimoire I found in the ground outside Durgan's Battery to save some gold on retraining spells, and then ended up spending the gold to learn some spells anyway, some of which I know I grabbed out of Aloth's book. There was definitely a lot of looking through various grimoires and swapping them out though etc before I figured out what I wanted to do. I *think* I also had one fight with some monsters somewhere in a White March zone.
I know I saved (ie: quit out of game since its a trial of iron file) at some point in the middle of doing that stuff. I apologize that none of that is very specific.. it was a few days ago now, and I didn't think to record things that led up to it at the time /: