Theres a problem with hunters when the targets are imunne to hunter's mark. The bot keeps trying to cast hunters mark all the time. Everybody can see it and can report you.
Without a log that demonstrates the problem, we've absolutely no way to chase this. It could be a bad Combat Routine, a bad user installation of Honorbuddy, a malfunctioning Plugin, a very peculiar WoW environmental situation, or hundreds of other things.