Besides, if his posts are in trashcan... shouldn't their number be shown as 0? Perhaps a mod can bring more light here...?
I am not sure, but their post count may be corrected once theymos does a recount.
See the post I quoted below.
I do recounts from time to time.
Perhaps there was a glitch at some point, due to which these users were not ranked up...?
Although those posts have been counted, they haven't increased their activity. Their activity is zero and that's why they haven't been ranked up.