It turns out Stalwarts don't want to stab rock piles. Since there's no way the Stalwart can get to that rock golem without stabbing a rock pile (and without turning his sword, which he didn't think about), he doesn't move.
So I tried changing the Stalwart's don't-stab test from pMonster->
IsFriendly() to pMonster->
IsAlive() && pMonster->
IsFriendly().
With that change, the Stalwart dies earlier given the solution on the scroll. The room is possible, but trickier. My demos for
TCB:Frozen Depths:1N2W are unaffected, but I don't know how many other rooms in other holds might be affected. Mike, is this change worth checking in?