Currently, when you ban an existing member of your group, that generates a past member record. If you proactively ban an email address (someone that is not currently a member of your group), that does not generate a past member record.
If you unban someone, regardless of whether that was a proactive or not ban, that also generates a past member record. This is basically a duplicate record (for members who had been banned).
My proposal is to eliminate the creation of a past member record when you unban someone. That fixes Andy's problem.
Please let me know what you think.