It's a handball. He gained an advantage by the ball hitting his arm. Personally I think its clear cut
Agreed, any game I have every played whether it be Sunday morning or 5 aside. I would have stuck my hands up and said it hit my hand, practically every one would. It's the spirit of the game.
No one can complain about that decision last night, it doesn't matter if it wasn't deliberate, most fouls and offsides aren't deliberate. But a free kick is still awarded.