You are right. There's one 554 for the group guidelines, and three for bounce probes. So the log entries are not, as I formerly suspected, coming from other groups. They are coming from the bounce probes themselves.
So although my bug report still stands in that I don't think separate log entries "is bouncing" should be created once the member is already blue "B," the underlying reason I guessed for the multiples (group guidelines from multiple groups) is incorrect. I am seeing more or less what you are seeing in the email delivery history, except that there are more bounce probes in my member's case, probably because I sent one by hand.
I'll go into my bug report thread and correct this.
Messages are the sole opinion of the author, especially the fishy ones.