Sorry to say, but if it's not on the screen, it's not in the logs.
Please can people giving inductions be clear, the netbook is there as a
convenience but not to be relied upon. It is the responsibility of the
user to ensure they time their cut, as sometimes this part of the system
fails.
If you don't know how long it was, please estimate and err on the side
of generosity.
Cheers,
--
Martyn