It is not only the behavior of the bot. And eaven a absolute human look-alike bot will get banned. I use GB since 2012 with one account and didn`t get a ban. I don`t eaven use private profiles, I use profiles that are downloadet thousend times from here and I use them since the MoP release.
As some GMs already told, there is a system that triggers if you collect Item X too many times in a certain period without doing something else. They eaven suggestet to go to a dungeon every once in a while, because real players also get banned if they farm long enough, for example to get mats for the ingi mount.
Another point is to just avoid player reports. So just don`t get to close to others, so that they cannot watch you when you farm. And If they watch you and follow you, just quit and don`t let them watch you gather more than 1 or 2 nodes the same way.
Those are very simple rules and I wrote them about 100 times here. But all the time I read stuff like "Gatherbuddy is bad, we need a new botbase, I got banned after 10 days of farming only 6h a day..." To all those..... Try farming only 3h a day by hand for more than one day. It will drive you crazy.
And if Blizz takes a look at you behavior and your toon did nothing else than farming for the last 2 weeks (no dailies, no quests, no dungeons) its not that hard to detect that you are a bot.