I'm new to SE, but I started noticing that the community user bumped up this question that was answered by the user. Because of the two day waiting period, the user probably forgot to accept his answer. A lot of users probably come to the SE sites just for questions and sometimes don't come back to check their inbox to see comments asking them to accept their answer. I initially thought this could be solved by adding a rule to the community user not to bump up such questions. But I later I read this meta post and started thinking about why isn't this a moderator privilege. If this was a privilege, the site could get rid of a huge number of old, unanswered questions.
Another example of a self answered post: Is this a Python quirk or an imperfection in the Raspberry Pi input?