HA !! got it ( I think ) !
Can anyone confirm my thinking / logic on this ?
When the power to the Pi restored at around 02h00, the Pi had no internet connection ( fiber routers were off ), and the Pi must have defaulted it's internal time to 00h00
So the process that is logged as 00h00, actually ran at 02h00 real time.
The process logged at 03h00 actually ran at 05h00 real time.
When the routers were powered on ( around 05h30 ), the Pi got internet connection, and updated its own internal time from internet time, and the next cron / scheduled job ran at 06h00