You did the right thing. I'm a soft touch though; I'd have manoeuvred it for them and given them the benefit of the doubt-my parallel parking was dreadful for many years. :)

I used to often see an elderly lady trying to park in an empty roadside carpark, It used to take her many attempts everytime. Often just going back and forth without a clue of which way to turn the wheel, While giving it about 6000rpm and slipping the clutch.

One careful lady owner? Hmm....

I think the OP did the right thing.

There is some incredible ones on youtube Jamie.

Some years ago I overheard a snippet of conversation on a bus about a man who was working as an HGV driver despite the fact that he'd never held a legitimate driving licence because he was an epileptic.

That is rather interesting as you have to have a medical examination to obtain a provisional HGV licence and then to have a medical at 45 and every 5 years after until your 65 at which point you need a medical examination every year.

The Ironic thing is, That car drivers don't have to have a medical examination they just fill in a form themselves and sign a declaration that they have told the truth. This is how a sizeable portion of the car drivers on the road don't have eye sight that meets the required standard.