If you want to be really safe, stop botting for a few days and play by hand.
I hand this same thing happen to me while botting up my first character a few weeks ago. Some dumbass whispered me to help him with something and when I didn't respond he said he reported me. I chilled for a few days and then when right back to botting 24/7. Not a peep from Blizz.
My guess is you either have to have multiple reports out on you before they look into your account; and/or they have to see some egregiously bad things to ban you off of a player report. Blizz isn't going to get rid of a paying customer because some other paying customer got butt hurt over someone killing a mob, not helping them, etc.