Changing an IF Fly call???

[parrothead]

Bases loaded, I think it was nobody out. So 3B was even or slightly up in "corners in". Batter hits what should be routine pop to 3B pretty high Umpire immediately calls IF Fly, but my 3B (12 yo) playing in, didnt turn proper, kind of got on heals a bit, and balls ends up falling and rolling away a bit. So runner at 3b scored, maybe even runner at 2B.

So fine, IMO batter was out because of the call and 2 runs scored and runner at 1B goes to 2B. So their coach goes to the umpire and asks for "help" on the IF fly call and they overturn their call and put the batter at 1B.

So No.1 it was not a terrible call in terms of IF fly, its not a ball that ended up out on the grass in LF it was a routine ball that our 3B misjudged and landed behind them, the point I made as to why these calls cant be overturned is that what if the misjudge went the other way, what if the 3B overran the ball it didnt get away from them? then what? I have them throw home, throw to 3B throw to 2b and then ask the umpire for help? Overturn and give me a triple play?

IMO for that very scenario, that call cannot be overruled or changed. What gives? Also, if it cant be, and umpires were, is that a protestable call? My thought was that it was because they were misinterpreting a rule which was changing a call they could not but they said the initial call was judgement so not protestable.