IMO,
It's better to admit that you may have missed the play,
than insist you are right,have the coach watch the tape later and see you were wrong, and lose credibility.
The line we like to use in Utah is,
"You're right Coach, I might have missed that one. If we have a third referee, we probably would have gotten it right!"
Two years ago it was proposed that we go to three person crew, it was rejected by administrators! NIce huh?