Meh, I don't find it to be in unacceptably bad taste. The comment was made more out of sympathy at the horrors of paralysis than out of cruelty or a desire to offend. It's "gallows humour", not "a sick joke".

Let's save that discussion for when you've spent a good part of your life in a wheelchair without a means of expressing yourself directly, other than through some electronic gizmo.

You're making a joke at the expense of a guy that has had just about every card in the deck stacked against him and that made in spite of that more of his life and did more for us all than you will probably ever do.

If you don't see why it is in bad taste then I'm really sorry for you, if you think that that was 'out of sympathy' then I must have a big problem understanding English, and I hope I'll never be on the receiving end of your sympathy.