The AFL has stood down two timekeepers and apologised to Fremantle and Gold Coast after a "significant" mistake during Saturday's close match.
The league confirmed on Monday that an extra 39 seconds were played late in the match which the Dockers won by seven points.
Fortunately for the AFL, the error did not affect the result as Fremantle's Tendai Mzungu kicked the last goal with only one second left.
The Dockers were already in front with 39 seconds to go.
The league confirmed in a statement that the time clock was not restarted at a field bounce with seven minutes and 55 seconds left in the last quarter.
"The clock was correctly stopped for a field bounce, but was not re-started as required when the umpire bounced the ball and there was 39 seconds of play until another stoppage occurred," the AFL said.
"From this point, the clock was operated correctly until the final siren, meaning an additional 39 seconds of match time was played.
"Both timekeepers have been assessed and marked accordingly on their match performance, which will see them not eligible for selection for upcoming matches in Queensland."