I tried something different, and was able to crash the game.
If the hero is leader and I open the inventory, switch to the DK and drop item's onto the hero's portrait until he becomes overloaded, trying to move after that will crash the game. If I switch the DK to leader first, open the inventory, drop items on the hero's portrait until overloaded, then everything is fine and he just can not move.
Try it and see if you can avoid the problem that way.
If so, then just the normal process of offloading junk to sell (and excess food and trap/alchemy material) onto a summoning doll will pretty much render the problem moot.
I tried this in a new game, using a chest and a couple barrels dropped onto portraits. Dropping onto the follow's portrait was fine, the leader would crash trying to move (directly from the ground, or from the follower's inventory). The disk version was fine either way.
