Digital Tacho Display not the same as the print out

The other day I was running very close to 4 and half hours driving time. By the time I was off the bay my display said i had three minutes left. I parked up and thought all was ok. My printout however says I over ran by three minutes.
Has any one else seen this where the display seems to differ from the printout?

Thanks

You pulled off a bay at 4h 27m ?
That’s brave.
It’s not uncommon for tachos to read a min or two behind, then catch a minute or two later, as you may have just found out.

may be at the start of shift was driving 6 minut after stop press to long POA and start drive again .

Dav1d:
You pulled off a bay at 4h 27m ?
That’s brave.
It’s not uncommon for tachos to read a min or two behind, then catch a minute or two later, as you may have just found out.

It was one of those days where it was all going bad, laybys full , depot busy and no free bays,but I had my eye on the driving time on the display and I know according to that I was safe. So i was not a happy chap to be given an infingment