It could have happened to anyone - but it happened to us. Got a phone call a couple of nights ago from sons nurse. They'd taken him out for a visit to the local docks/marina (good) but not noticed the car park closing time (not so good) and got locked into the car park (bad).
Now for anyone else, this would have been a significant inconvenience, the sign was there, so tough. For my son, he was 8 miles from home, his adapted vehicle was locked in with him, he needed medication to control his epilepsy, his suction machine battery would run out and he can't use public transport. For him this was a major problem which could easily have developed into a medical emergency.
There was no contact phone number on the sign and the police were completely uninterested. They only got interested when I mentioned the phrase 'bolt cutters'. Fortunately, another driver, also locked in managed to locate a 'member of the public' who had a key that fitted. (Don't ask me, I didn't ask how.) Score 1 to people power, 0 to officialdom.
I only mention this to illustrate how problems for ordinary people can become disasters for people with disabilities - and the powers that be often seem more interested in the rules than the outcomes.