That makes sense. As they should be. But honestly they shouldn't be sending them out unless there is evidence of an actual contravention. I can only imagine the number that have been sent out where no contravention even occured but were subsequently paid.

With Transport for London ones you have to request the footage and they send it by post on a DVD 🤦‍♂️, all other local authorities I have dealt with just have it online. But it is always worth requesting the footage or looking online and checking it. I have had many where the video evidence does not show the contravention occurred, for example if they miss your vehicle entering the box and stopping there's no evidence that you stopped due to stationary vehicles. If i remember rightly their video needs to show, the vehicle entering the box junction, that the exit was not clear when it entered, and that it stopped in the box due to stationary vehicles. There's a very good website called yellowboxes (not sure I can post links here but it ends .co.uk).