The weird thing about this is the part about their call not being reversible. It's not even a matter of reversing it.
Infield fly is contingent on it being a fair ball. The ball wasn't fair, so it's not an infield fly. There actually is no call to reverse here if the umpires understood the rules.
Also it's very easy to "reverse" an out into a foul ball even if that's how you want to look at it. It doesn't require any special thinking. Just... everyone go back to where they were, strike on the batter.
Infield fly is contingent on it being a fair ball. The ball wasn't fair, so it's not an infield fly. There actually is no call to reverse here if the umpires understood the rules.
Also it's very easy to "reverse" an out into a foul ball even if that's how you want to look at it. It doesn't require any special thinking. Just... everyone go back to where they were, strike on the batter.