i got the same done to me, i basically used lazyraider for about 1-2 months before starting up BGbuddy again. and i kinda learned my lesson i only do it 8-10 hours a day while im at school, as opposed to 24/7 like what i did for about 3 years before finally getting any form of ban.
I would say 1-2 months to be safe. seems to me that anything less than that would look suspicious, as maybe they put you on a watch list for a couple weeks before moving on to the next guy, they cant keep your account flagged for ever, it would take alot to monitor everyone for longer than that imo. but its all speculations, no one knows how blizz operates on that side of things.