Policy etc should already have some sort of guidance, if not, I guess this is starting to make that happen.
So what did the driver say when asked about them? What were they? Driving for 4h31mins is quite different to driving without a card!
What has the TM/Company done to help them understand how and why it happened, and then how they can avoid a recurrence - at least of the same thing, were they pushed to do it due to silly job allocation, traffic problems.
Same problem once a month for 3 months is quite different to one big every 3 months, do they just keep missing the limits with good intent or just don’t give a sheet.
No hard and fast rules, unless its serious infringement in which case they could end up going straight to disciplinary and final written warning / dismissal