The whole hypothesis is based around the toxic cabin air story, which is largely pushed by Tim van Beveren, who acted as the 'expert journalist' here.
You may google this guy and come to your own conclusions.
This guy has written a couple of investigative books that touch on some aspects that deserve to be more thoroughly worked on. The way he promotes it, though, makes me think he is more interested in selling books than actually helping the industry improve.
The cabin air hypothesis does not only imply the alt-selection knob mysteriously turned by itself (twice!), it also doesn't have an explanation why the door wouldn't open.
And of course the date wasn't carefully selected to maximize publicity...