Delayed Flight - "Exceptional Circumstances"


Apologies if this question has already been answered – if so please point me in the right direction.
We were delayed 10+ hours on a 10 hour+ BA flight from SJO to LGK. The reason given (both on the flight and later) was that a pilot had been injured (leg injury while out jogging) between flights and because the plane needed 3 pilots this delayed the flight.
BA provided a hotel at SJO end + meal and have accepted a claim for a hotel at Gatwick end (arriving 10.40pm made onward journey impracticable).
However, BA has refused to pay the delay compensation on the grounds that it is covered by “Exceptional Circumstances”.
Having search on the internet all I have found so far is various “claims” firms claiming that staff/crew ill health is not an “Exceptional Circumstance”. Some claim this has been established through legal precedents but (understandably) don’t provide a link.
So, can anybody provide any info on whether this is covered by “Exceptional Circumstances” or point me in the right direction to find this out please? Thanks in anticipation.
Replies
Location of airport irrelevent ,nothing in the regulations to differentiate between airports
I think BA have fulfilled all their obligations in this case.