You missed the point. The phone didn't wake up, but his report time was moved back by a couple hours.
And no, as far as i know there is nothing in EU-OPS or EASA FTL against that practice, except a rather feeble plea to not disrupt sleeping patterns.
However, if you get fatigued during duty or know before you start your duty that you are very likely to become fatigued you should be able to call in unfit to fly, either during the rotation (if it consists of several sectors) or before the start of the duty.
Or simply roll over and sleep for another three hours.