"That is slightly reassuring. I got a friend of mine to block me and see if my comments showed up on a mutual friend's status, and they didn't at all. So the idea that my friend was using some weird facebook workaround to avoid that seems concerning."

Could that be do to who is set to be able to see your(the) posts? Like friends, friends only, etc? Cause it would make sense if it was a tighter lock down on the post that may be why yours were not showing while the other person may have a looser setting in use. Random interjection...