The definitions of what exactly is and isn't high risk is kinda up for debate. There's just kind of a lot of superstition and anecdotal evidence in "banrates".
People theorize that rate of clicks, how repetitive a task is, amount of real players nearby, likelihood of being reported, likelihood of breaking, etc all contibute to potential risk. I've heard anecdotally that barb fishing is "risky" as well due to how repetitive and heavily botted it is. But it's really hard to say.