Yeah, there are obviously going to be exceptions, especially in the earlier games. In the later games, like in all of GMK's examples, it's very clearly done on purpose to the point where he probably tests each pattern specifically for bomb resistance (as the developer should be doing).
I'm almost thinking Unilateral Contact is done on purpose though, since you almost always will get a border for it, and it guides you towards the middle before shooting the next wave. It's pretty unlikely that you wouldn't just naturally use the border to cancel the bullets there, so while it's possible ZUN just overlooked it, to me it seems too conveniently set up to be an accident.