I agree that it was a poor sequence of events but WestJet has done quite well I'd say. They tried, tried again, and are owning the result that was largely out of their control.
I have unfortunately had a lot of similar experiences with customer service at large US airports, so not much to say there.
Having been similarly stranded in Halifax by the same storm I was happily helped by a Good Samaritan who filled her car (her husband picked her up) with as many passengers who were stuck as she could. So good people are still out there.
And finally...the storm was very well advertised (forecast). Given his mobility issues this passenger could very easily have called WestJet and had his return altered: earlier, later, or different route. We don't always have to let other people do the work for us.
I regularly make these arrangements in order to get to/from work on time and Air Canada, which I usually use, makes changes without penalty. I would be surprised if WetsJet did not do the same.