I do not know if this is the place to pose a possible bug and as I am super new to Stack Exchange (honestly any forum for that matter) I apologize if this out of place.
A couple days ago I posted a question anonymously (as a guest) and then was prompted to create an account if I wanted to edit my post. Doing this created a second account even though it was under the same email. My accounts were created very close to one another (based on my user_id for each account). I did not make two intentionally.
Referring to the question above as it is possible that it is similar to my experience. It appears to me that user Zostalesfdc may have had the same issue I did when creating a new account considering their user_id's are only 1 apart. I may be wrong but it caught my eye.
It's possible the ability to allow many accounts to share one email is a bug when dealing with a guest account turned new account or maybe it's an intentional association but it's very easy to create two accounts accidentally this way.