It's the Fireball spell that has trouble. The Windblade spell should work OK. I think the collision shape for fireball is larger than other spells so it impacts the wall immediately if you place the face too close to a wall. Maybe they were trying to make it easier for the player's fireball spell to hit enemies - if you notice, the player's fireball spell impacts enemies even when it's noticeably off target just like the Stoneface's. I expect a fix would be in the sfx.dat file which is basically a combined PRF file for all the spell effects.
I'm assuming you have the "turn" setting to off, so he's probably turning because the "Face To" button is pushed. It lets enemies rotate to stay aimed at the player during the attack animation. ie increases the odds that a ranged attack will hit a moving player.
I'm assuming you have the "turn" setting to off, so he's probably turning because the "Face To" button is pushed. It lets enemies rotate to stay aimed at the player during the attack animation. ie increases the odds that a ranged attack will hit a moving player.