It could have been earlier in the drive as in 30 minutes before, or something ridiculous like that. That was complete weasel wording.
Also, Tesla can mistakenly think you aren't holding the wheel when you are. Happens to me all the time.
Regardless of the criticism of Tesla here, surely the driver wasn't watching the road, or otherwise this wouldn't have happened.
It's not clear to me whether the "several visual and one audible hands-on" happened right before the crash (6-10 seconds), or the minutes before.
"The driver had received several visual and one audible hands-on warning earlier in the drive ... and the driver’s hands were not detected on the wheel for six seconds prior to the collision."
https://www.tesla.com/blog/update-last-week’s-accident