Football Rules: 5th Down After Penalty - What Happens?

Question
What should happen if the offensive team runs 4 plays without a first down, but due a mistake by the offical receives a 5th down to punt football?

Answer
Hello Don,

If it is caught, even after the punt, the ball should be brought back to the spot where the fourth down ended. I am not sure if it would fall under the " A play has already been completed rule". Meaning that once the ball was punted, the play can not be corrected. Very strange rule, but that particular play happens more than some would believe. In the NFL, I don't believe that play can be "challenged".