I'd say it's this. It's not going to be one single common denominator; it's a chain reaction of things. You get reported, Blizzard's "anti-bot program" or whatever looks at damage/healing and weights it against movement and inactivity, number of current reports, number of previous reports in X amount of time, repetitive actions, amount of time doing the same activity {bgs, spawn camping, other common bot activities} blah blah blah and if you hit the magic "if it walks like a duck, kill it" in its heuristics you get flagged for an account action.
It's probably the exact same thing people complain about with
transferring gold between toons and
farming mobs for XP or
whatever. PvPers
aren't the only ones hit recently. Combine it with
GMs who don't know WTH they are doing and you get the "ban now, repeal later" action we tend to see waves of any time they are working on killing bots. So speculating that it's this one thing or that one thing is pointless. They'll tweak things until they are done purging the bots and these suspensions will be back to freak occurrences again.