For context: watchmakers have often used 10:10 for marketing materials because it's symmetrical and it doesn't obscure the brand logo, which usually goes below the 12 position. Apple uses 10:09 probably because they want to be "ahead" of everybody else.
Similarly, iPhones are all set to 9:41 in marketing materials because that's the approximate time Steve Jobs introduced the first iPhone back in 2007.
You realize the event wasn't live, right? And Tim's watch clearly shows 10:09 the second he shows up in the video which was 10:01 at the latest "real time".
I know it isn't live, and it shows because they've been sloppy throughout. Check out his watch at the 20 minute mark, it's way off.
In general, Apple's presenter's watches (and demo devices) show the local time for live events, and they tried to do that here but obviously didn't do a very good job.
Similarly, iPhones are all set to 9:41 in marketing materials because that's the approximate time Steve Jobs introduced the first iPhone back in 2007.