Yes, examining work unit pages, I see that it is a race.
In work unit 630737405 my computer got its GPU task 10 minutes earlier than the other computer, and the task's run time was only 101.41 seconds, but its "Time reported or deadline" was six hours later, whereas the other computer reported within seven minutes.
Why would my computer (doing nothing else at that time of night) have such a long delay?
Late-night Internet outage is a possibility, but seems unlikely.
Could my computer be queuing up too many tasks?