YANBU, OP
and you have NOT fat-shamed
but some posters hve been quite vicious towards you
A couple of posters have criticised the man for getting that fat, but you didn't
Personally, I would not risk it.
The hospital should have professional transport available for those of his size.
It may be inconvenient for him and embarassing to ask, but it would be far more embarassing for you to ask him to pay for damage - and of course you can't really do that
"It was naive at best to think that even an exceptionally heavy person was going to damage the suspension on a 1.5 tonne vehicle with suspension designed to handle between 2 and 2.5 tonnes"
and yet, several people have posted about how their car has indeed been damaged in this way:
seat, upholstery, suspension etc
And a normal vehicle is NOT designed to transport 2-2.5 tonnes load.
The OP has stated her vehicle, according to its manual, can only carry a few hundred kg in the passenger compartment
As has been said repeatedly, a load of over 30 stone - and we don't know how much over - has very different effects, depending on how it is distributed over the area of the car,
whether it is all in one seat, or over several seats