Moon jumping can be spotted.
It's sad to hear that their are really coded to do that stuff. I only knew about Moonjumping and Instant MT before.
Although you have to realize the majority of people don't do these. Yea, anyone could say: "How do you know?" and I don't. But honestly, I trust the people that I played with that they didn't. And if they did, then that's their decision and I need not worry about it.