I’ve had it go both ways too, with a couple of times where an enemy was able to throw a projectile at me from another room because there was a tiny hole in the ceiling or a high wall that the projectile could path through.

More than that, however, were instances where the game told me I could hit something just fine, only for it to not work as my projectiles/spells smack into some obstruction that was apparently not factored into the hit calculation.