By using the reset, did he put everything back to factory settings, resulting in our password & other styored information being lost?
BINGO. Yes, treat it as if you just brought it home and opened the box. You'll need to run setup from inside the same network the Slingbox is on and go through the initial configuration steps as if it were new.
If you got one channel but nothing else, you probably needed to rescan your channels again for the new location. But since it's reset now, you'll have that opportunity when you run the set up.
One thing that won't change is your SlingID. That stays the same even if you do a hard reset.
Hope this helps,