Auburn goal line touchdown call and review

I get that if you can’t see the ball it can’t be overturned.

My question is that if they can’t see the ball how can they make the touchdown call so late anyway? They had to clear the pile before signaling the touchdown and at that point anything could have happened for him to get that ball across the goal line after he was down. How can you call a touchdown that late?

I know there’s no better way right now but just a weird approach to a crucial situation for all games.