@Kayleigh
Earlier this morning I permanently banned four accounts that had 0 posts, 0 profile messages, and their source IP was a commercial web site. Plus the account names were clearly a type of product advertising. They had been on the forum at least 4 months with no detectable activity which is how they lasted that long - but they cropped up when another member alerted us to their presence.
Therefore, yes we will ban members and deactivate their accounts. But my first paragraph tells you what criteria I used to remove them.
I have also banned a couple of accounts for explicit vulgarity of such an extreme nature as to imply a desire to commit a physically violent sex act against a member who dared to disagree with the person. Again, from your description of the account, I don't think it would have been banned for the "respect for members" rule.
However, Jon DID change the forum software from vBulletin to Xenforo. I don't recall exactly when it happened but it might have been after 2018. He tried to copy over all legit posts and members but who knows? If the account appeared inactive for some reason, it MIGHT have been skipped even though I know Jon said at the time that he would try to avoid doing that.
Can you tell us what name was used for your colleague's account?