L3 Dismount Query

It would be illegal. Releases at level 3 must start below prep level, however they can land prone.

Agree with championprincess.
That release move is not coming from below prep level and also land in prone position (not cradle: face up in pike position) so can´t apply any L3 dismount or toss rule to make it legal.

I hate to be a stickler but this isn't a release move, it's a dismount as UKSAS stated. It is still illegal but not for the reasons that have been stated. It is illegal because it violates rule D under level 3 Dismounts.

"Only straight pop downs, basic straight cradles and ¼ turns are allowed from any single leg stunt."

I know that it doesn't really matter, but if you look at it as no release move can begin above prep level and you are in a partner stunt, then you can't cradle from a full (or extension, whatever you call it). When in actuality you can twist from two legs in a full (or extension). You always want to make sure that you are looking at the correct section of the rules when trying to find a legality. Even if you could have caught it like that from a toss, a toss has to originate a certain way. You can't dismount from a one leg partner stunt, but call it a toss because it fits your needs.

A dismount is to a cradle or to the performance surface, and this is neither.

I´m not agree with InfinitiElite, I find this in the USASF Glossary and may can help better:

Dismount: The movement from a stunt or pyramid to a cradle or the performing surface. The movement from a cradle to the performing surface is not considered to be a dismount.
Cradle: A release move in which catchers, with palms up, catch the top person by placing one arm under the back and the other under the thighs of the top person. The top person must land face up in a pike position.

But I think we all are right, is illegal in L3 do that... that release move lol