That is the thing- if they called it a 1st down on the play, then there was not enough to overturn it. If it is called short of the line- there is no way to have evidence to overturn it.There's no way you can tell from this picture that the player is out of bounds or not. He's in the air.
Now if there's a shot that shows a body part touched the sideline, that's different.
Watching live- seemed obvious 1st down, but with replay- you could see a good possibility the ball crossed in the air short.
Regardless- what ever was called on the field, was going to stand.