From a past conversation on the Customer Support forum:
The sticking point for a lot of people seems to be how quickly those addons can find the deal and pop up that button for the player to press. We think of it as “the second after clicking the button”. It feels FAST.
In order to be botting, though, it would have to somehow emulate the player action of clicking the button. The only real way to know if any auction addon out there does that is to try them and see how they work. If one actually does buy without prompting, absolutely YES, report that. If not, you’re just running into the fact there are potentially hundreds of people all waiting at any moment in time for their addon to find deals they’ve asked it to look for and clicking [Buyout] ASAP when one is found.