Received court papers! Advice please.

System

You can call my impression wrong

Nope can't be wrong as you were there. We weren't.

The points the judge made are all valid apart from the "grace" period. The idea of the "grace" is to stop "de minimis" matters getting to court. The contract is breached 1 second after the ticket times out but 10 minutes is custom/practice.

If the judge decided to use a strict interpretation of the contract and ignored custom/practice then he/she would have their reasons. Or the issue wasn't overstaying at all.

However IF we assume the judge is correct (always a good starting point) then the issue becomes why the judge assumes the "grace" period is not obligatory but a gift by the landowner which can be challenged if the facts allow. For example in a car park which only allows 1 hour parking, the grace period can have a significant effect on income if drivers assumed the 10 minutes were free. In a 24 hour car park, the 10 minutes would indeed be "de minimis"

If the OP were to send the papers to Coupon or another trusted member, then the detail could be examined as it may be more significant than your think. Already we have seen on Pepipoo a LA offering 1 hour free - including the 10 minute grace. And since they all talk to each other, there may be a movement to incorporate the grace period into the tariffs.

The PPC's eat, sleep and breathe these so it is not beyond belief they have another campaign planned to remove standard defences.