What is the call??

[JLC]

Had a weird situation in a 6th grade game last weekend. Team A has throw in after made basket, but calls time out. Team A is slow to come out after T/O, after warnings from ref, so he puts ball on the floor and starts his 5 second count. Defender from Team B sees ref counting, gets confused, and runs out of bounds and passes in to one of his teammates. Apparently, ref is also confused, because nothing is called. As team B is running its offense, coach from team A is yelling about wrong team taking ball out. Ref stops play to get things cleared up. He realized mistake at this point and gave ball back to team A. I know this was the fair thing to do, and it was only 6th grade game. But am I correct that technically, he was wrong. This was not a correctible error, so team B keeps possession and ref pays more attention next time. (I was only a spectator at this game)