I replied to OP but I also need to say that I have definitely been the bully before. Very very inept coworker that after months of mentoring started to blame me for their short comings. So, after that, I stopped being so nice. There was only so much bullshit I could handle.
So at the time, it felt justified? But looking back I wish my response was to just ignore them.
The creeper paradox: the harder you try not to be, the more you appear to be.