It's not even unbreakable objects, the AI doesn't seem to understand the concept of breakable objects.
SPOILER
For example the Frogs in the mines, you can lure them back to the main living area, but a crate in the way, and they will get really confused. Eventually they might teleport over them, or surface fire with burn the box enough, but NPC pathing doesn't consider objects to be moveable or breakable.
