These posting times could lead to something. He cannot post two posts at the same time (well,could, but most likely not). But Joe and the actual person are, for example, awake at the same time. Would need some statistics.
I think this could be a viable attack.
It would involve some serious page-scraping of bitcointalk. Assuming you guys do that and then have the posting times of all bitcointalk users you could compute a likelyhood of each user being "real me" using various heuristics. Especially over a long period of time, combined with my roughly known timezone info and maybe some manual language analysis in the end, this could potentially boil it down to maybe a handful of users that would then be suspects.
I would consider that to be a pretty dangerous development for my anonymity.