A traveller can't even FIT in an airplane seat can it? I wonder how that worked before since they said they had been allowed to use it on previous flights. The thing is massive! You can transport in a wheelchair right? I wonder why they just didn't use his chair. I'm assuming he has one of course, since he can't walk.
You cannot fly in a wheelchair. There are no empty spaces with wheelchair tie-downs in a commercial aircraft. You can transport in the wheelchair until you get to the aircraft door but then you have to walk or be carried to your seat.
I'm also surprised that they were able to get that seat to FIT in the aircraft seat on the previous flight. I have a Regent (same platform as TP) and it's not FAA approved because (I was always told) that it was too large to fit in a standard aircraft seat. None of the seats based on the TP (Super Elite/Husky/Regent) are FAA approved.
It's an unfortunate situation all around. However, if the CR did actually fit in the aircraft seat and none of the other passengers were inconvenienced by the size of the CR - they could have looked the other way rather than creating a potential public relations nightmare for their company. Being "right" doesn't win a war of public opinion when the issue involves a child with a horrible degenerative disease.
If, however, the CR didn't fit and there was no other option to accommodate (like moving to a larger business class seat), then I'm not sure what the airline or its employees could have done.
FWIW, I heard somewhere (Lifesavers conference, maybe?) that the Cares harness can be used in special situations like these beyond the stated weight limits. Or maybe that they were petitioning the FAA to allow it's usage for SN kids over the wt limit? I can't remember the details but it was along those lines.