I know there are two sides to this story but my "gut" goes with the cruise line.
Yes, this person booked a suite in order to have more room but he did not book a Handicapped Cabin. A regular cabin, even a suite, is not handicapped accessible. It was said he paid "extra" for a butler to help him. I'm sorry but a butler is not a personal attendant. He "assumed" that the butler would be his personal attendant and help lift him over the threshold to the bathroom and to lift him after falling off the toilet.
The cruise line has a huge liability if they lift people and injure them. They also have a huge liability if this person falls out of their chair or is injured in the cabin and is unable to get help.
I often need assistance on a cruise and I would never dream of not traveling with someone who would be my personal attendant. I personally believe it was very irresponsible of this person to travel alone. BELIEVE me I know what it's like to lose some independence but there are compromises that must be made.
Accommodations need to be made for people with disabilities but the cruise line personnel being the personal attendant is not one of them.