In a December 13, 2015 game between the Atlanta Falcons and Carolina Panthers, the time of possession of the two teams was recorded as:
Adding these two gives a total game time of 59:42, which is 18 seconds short of a full game. Is there an explanation for this? Or is this simply an error in the source data?
Another game I found that has a similar discrepancy:
That is from NFL.com. It's one second short of a full game. Another error in the data?