After almost a year in coma my wife is having to learn the basics again. How to walk, how to talk, how to feed herself and how to not argue with me at the top of the stairs again.
I am not sure if it is wise to joke about something like this. Are you sure you this is something you want others to know about?
Of course. I do not consider such comment abusive in any way, it's my suffering and I should be allowed to lament on it
If I may be truthful, your comment does come off as being abusive. It gives off the vibe that your wife deserved it. If I was you, I would not say this to others because I think most people would judge you more than your wife. 
Well, it's how I feel and I don't give a damn about what others think.
You should try to support your wife and work together to get her healthy. I am sure she doesn't want to be in the state that she is in. It's going to take quite a bit of effort to get back to normal, and she will need your support.