If i would knew the perfect method to catch someone using ranger, i would do it with joy. Problem is, i don't think there is such a possibility. I don't know how they did there, on retail. It's not really that much in that thread. Just that some ppl got banned.
Anyway, atm there won't be a better protection on RPG. We will have to continue like we did until now, banning for what can be proved. If you remember the antibot that was added at beginning of 5x, it was pretty good but only a "beta" build. Well, the guy that made it got some problems that sadly, he didn't resolved until now. That's why work on it stopped. But sooner or later he will return to continue his work. It is also possible we will have someone else doing a custom protection, but not right at the moment. Right now admins of RPG are busy at work with, well, i suppose everyone knows by now with what : )
For now, just enjoy RPG and remember that time heals everything.