I've going through his answers and they are all high quality, and the answers he's supplied before the penalty was enacted have multiple upvotes. This user seems to be a great contributor to The Workplace, the antithesis of "troll account". I'm going to guess that whatever his transgression, it was removed for moderation reasons - especially if it was egregious enough for a one year suspension.
So what did this user do, or, more generally, what type of behavior warrants a one-year suspension? (Specifics need not be mentioned if it infringes upon the privacy of those involved in the transgression.)