Wtf does that mean they're appealing their own decision?
They're disagreeing with the judicial officer's decision so they're getting a panel of judicial officers to review that decision.
I think they will particularly be looking at the original judicial officer deciding that Steyn's tackle only went wrong because other people got involved and it wasn't his fault.
Isn't that half the point of outlawing tackles that go beyond the horizontal? They create a dangerous situation where if something goes wrong they can result in a catastrophic injury. If a tackled player is put in a compromising position and then another defender also gets involved in the tackle, it creates a far greater chance that something will go terribly wrong.
It is the classic case where the initial tackler is trying to pick the player up with a low tackle and the second one driving them to ground and once the player goes beyond the horizontal they have a player driving the top half of their body at the ground.