>What value did the comment have in the first place?

That comment is the only indicator that something may be wrong. Your next steps are the same as with any suspected bug, find out what the code is doing (seems obvious here) and then find out if that's what it should be doing.

That comment, however, is a good example of a bad comment. In this particular scenario, it's very obvious what the code is doing, so the comment should describe why the code is doing what it's doing. Much like should do:

    //set volume to 5
    x = 5;

Rather than:

    //set x to 5
    x = 5;