Seriously, the Chargers should protest or something.
If the lights broke in a night game, they wouldnt keep playing.
Lights vs. Instant Replay is about as horrible an analogy as there is. Lights are required...instant replay is not.
What they should do is if IR fails on the 1st call and cannot be used,then they should abandon it for the entire game to make it fair. If human error is going to decide the 1st call, then it should decide the entire game. You DON'T have to have instant replay. You do need lights.