I'm not saying it's an AYSO move. I'm saying that some coaches (either because they don't understand the mechanics of the back pass or because they are rigorously possession based) would call out the keeper for blasting it up instead of trying to retain possession. Like a kicked dog that's been kicked one too many times, the keepers then do stuff like this because someone else (in this case the ref) will get the blame from the coach/parents whereas they'll get the blame for "going AYSO" if they blast it up. There's also a decision to be made in clearing it that needs to be made clear to the keeper: ideally you pick out a player long to receive it....but if not do you blast it center and long, blast it out and wide, blast it to the wingers or to the backs (center long carries the risk of interception when everyone is out of position, out wide means it could very well go out). I suspect this team has been instructed to work on their possession, hence the decision by the goalkeeper, because you are correct: the normal default in this type of situation where your lb has mishandled the ball is to rocket it.I agree with you that many bad decisions led to the team being in this position of forcing the goalie to make this decision. I disagree with you that clearing the ball when you don't see passing alternative is an AYSO move. Preventing a goal is the primary duty of a goal keeper, not possession. A keeper needs to learn how to recognize when to pass and when to clear the ball.
A goalie with good footwork and accurate passing skills under pressure would be able to make that pass. I've see it plenty from goalies to midfielders, etc.
I'm also of the mindset that it's good this happened because the goalie and the entire team can learn from their mistakes. It's no big deal. It's how players get better through the years.
I disagree the pass to the RB is completable. The only way that gets there is if the two attackers from the opposite team aren't paying attention. And having it intercepted is way worse from the keeper's point of view (then it's entirely 100% his fault) than just trying to muscle his way out of it (I fought for it but the ref is the bad guy that called it against me).
As to whether it's a big dead, it depends on the age/level. As I said previously, flight 1 good for them for trying, it's how you learn...MLS Next what the hell were you thinking.