I can't understand why SW would make him disembark if he
could fit in the one seat with both arm rests down, particularly seeing as though he didn't even need the extension seat belt!
Even if the flight was overweight then they should be taking off freight before pax but I suppose it depends what the particular airline's policy is. In any case issues like that should be sorted out not only prior to boarding commences but prior to checking in all the pax. To single him out like that is blatant discrimination.
There are many cases when extra seats (EXST) are booked eg when taking service dogs so the dog has more room to move, a musician taking their prized cello onboard, a pax on crutches who wanted the extra space and larger folks who need extra space for personal comfort. This must be booked thru res as no facility as yet to book online.
I think QF & DJ are pretty good trying to accommodate requests for a seat to be blocked off
if there are seats available. I wouldn't fancy my chances if travelling on JQ or TT. If pax find themselves in a situation like this it would be a good idea to select flights at off-peak times for the best chance of getting a spare seat.
I remember ages ago helping a friend of my Mum's do a booking on Ansett for an extra seat as she'd just had a skin graft on her leg and could not bend it. The seat in front of pax was folded down to allow her to have her leg straight.
AN issued a ticket under the name "leg support" for an amount of a child fare (50% of full Y adult fare) which was the best one way fare you could purchase at the time - this was prior to 1989 (deregulation and end of the two airline agreement). The ticket was only to be utilised if the flight was full - it wasn't so the airfare was duly refunded.
Here's what US comedian Lavelle Crawford has to say about on the subject at airports (first 90 seconds of the clip):
YouTube - Lavelle Crawford - Being Fat
And another one about Southwest Airlines' policy (starts 1 minute into clip & runs for 4 mins):
http://www.youtube.com/watch?v=_N4dl1faW8U
Cheers Oz