Please see caveat below from the Parkrun website, not sure if the situation has been resolved yet but if your time is wrong please let them know as well:
Apologies, there was a technical problem with the timer on 22nd August. As a consequence the times below are definitely not correct. We are aiming to fix the times as soon as possible, but we need your help. If you timed yourself, please email your name, position and time to black-parkOffice@parkrun.com. Sorry for the inconvenience and thanks for your assistance.