No - not joking at all.
What is slightly disturbing about this particular case is why XC paid compensation. Would they have done so if the only toilet on a train had been locked out of use and an able bodied person had soiled themselves? If the answer is no - then it's sending out the wrong message paying compensation on this occasion.
Able bodied people are able to get on and off trains without assistance. This lady wasn't and was therefore basically trapped on the train because of the failings on that particular day.
If they hadn't paid out they'd have been left defending a difficult court case for them, with the associated legal costs, not to mention the reputational damage in terms of media interest as this lady is a paralympian with an MBE (that's down to how the media report, it's not this lady's fault she's more interesting/newsworthy because of who she is). To be honest if she can use her status to highlight that this kind of thing happens when it clearly shouldn't then that's fair enough.
Commercially from XC's point of view, settling out of court, which is what this is rather than being awarded compensation, with a confidentiality agreement attached that says that she can't discuss it further with the media is by far the least worst option.
This incident should clearly never have happened, everyone involved is in agreement on that, and was embarrassing for the person concerned so XC's response isn't inappropriate in any way, it's a sensible solution
as long as the procedures are looked at to ensure it doesn't happen again to anyone, be-gonged paralympian or not.