What most Lions fans and Cowboys-haters fail to understand is that few people are defending the referee because it is quite likely he heard it wrong or mistakenly thought the player running in from the sidelines (which is normally where the eligible linemen come from) was the eligible receiver.
What most of us (and some of the more intelligent media people) have been saying is that the play worked because the referee told the Cowboys #70 was eligible, not #68.
Why they were told #70 is a valid complaint for Lions fans, but saying the "Cowboys got lucky" when they were not told a non-eligible player who was lined up in the normal tackle position was going to run a route is ridiculous.
The play worked because no one covered him since no one thought he was going to run a route, much less catch a pass.
If they knew #68 was eligible, they would have tried to cover him. Maybe the Lions would have converted it, maybe they would not have, but we have no idea because 1) the Lions confused the referee and 2) the referee told the wrong eligible player number to the Cowboys defense.
If I was a Lions player, coach or fan, I would be irritated too, but I would not be blaming the Cowboys, but rather the referee for getting it wrong and the head coach a little for causing the entire situation by trying to be sneaky on a play that is designed to not be allow "sneakiness" by NFL rules.