[V12 - Ground Combat] Able to see/shoot aliens through wall corners

I've now encountered several places where I can "see" an alien who was enclosed behind walls, once in a building and twice in crashed "heavy scout" ufos. In all instances, it seemed to be caused by an alien who was in a corner tile; I think there might be an issue with the corners. In at least one instance, I was able to shoot and kill an alien from outside the ufo, with the shot passing through the wall corner. Note that this did not cause a crash, or any other detectable issues.

It would appear there is a literal corner-case in the line-of-sight code

I've had that as well

It's a known issue.