Is it not just easier and less tine consuming to drop to 50mph? It would’ve cost seconds instead of hours/days/weeks contesting a potential fine.
Yeah I get the point and it can be frustrating and leads people into ignoring gantry info because it’s wrong/not turned off when it’s finished with etc but ultimately it’s a few seconds lost and a few clicks of the CC and that’s it.
I’m sure you can contest it but you’ll need to spend time gathering evidence etc and ultimately they could say it was down to 50mph for any number of spurious safety reasons and its then game over for any challenge.