Staying on your feet

I was watching the super 15 semi finals this weekend and one thing struck me above all
and that was the pure ferocity at which they hit the rucks
And it was admirable and quick ball was got alot of the time
However i was under the impression that firing yourself like a torpedo over a ruck was illegal.
I cant get any examples at the moment as i am in work, but i will try when i get home.

So the question is will this be how its reffed at the world cup.
One of the ref's was NH so its not just a southern thing

My understanding : Diving over a ruck to hit someone or seal off the ball yes, but but binding (not charging) into a ruck and pushing a player out of the ruck no.
If youre dexscribing players literaly jumping over a ruck to hit a player then that would surely be charging regardless of whether they somehow managed to stay on their feet or not.