I think the invite idea is a pretty good one. That way if someone uses it against you, it's your own fault! That and if you got the suspicion it was being used against you, you could just not risk it after that point.
Well while that would offer another method(live coaching), there actually already is a fairly decent method with the replay system, given the fact that you can send your replays to other people to watch. Of course, there is a limited time frame with these replays since they expire once a new patch comes out, but it is still something.