When visiting the restroom, I've walked in on the same coworker sitting on the toilet three times now, from where he simply neglects to adequately lock the stall door. I definitely don't want to keep walking in on him, and, if I'm doing so, then perhaps others are also falling victim to his negligence.
Since he already knows I've seen him [thrice], should I just confront him directly about the matter? Would it be wiser for me to contact the building manager, or the office admin? Obviously there is some kind of disconnect on his end.. I use that stall nearly every day and I've never had this issue myself, or with anyone else.