The issue was one of passenger death arising out of exposure to smoke in an aircraft cabin in circumstances where a flight attendant had refused to remove the passenger to another seat location upon request.
The carrier's failure to reseat the asthmatic passenger in response to express requests so to do was held to have contributed to his pre-existing medical condition being aggravated by exposure to ambient cabin smoke, which caused his death.
Airline people will refer to the interpretation of Article 17 of the Warsaw Convention in such cases.
But it is of course always beter to prevent [such] 'accidents'. That's why I say to all f/a reading this forum: NOT all complaints are based on fake. Listen carefully to the passenger's complaints.
So it is better to find an immediate arrangement in such cases.
And do not forget that such requests by passengers, can be put on paper and the seat re-assignment or other additional service can be object of a modification on the passengers ' transportation contract also under the Chicago & Warsaw Convention. Some airlines have this document in different languages in the o/b PC. ( As in inflight upgrading, etc) Once you have this signed acknowledgment of satisfied request, your are quite safe. In the other case you could also try to get a signed statement why the passenger refused your arrangement proposal (and that is is not so easy to obtain).
The acknowledgment would eliminate fraud, and if not, would consist a base for your airline to recover the fraudulently obtained service...
One flight this f/a will never forget, is probably that one where (s)he did not listen well to the passengers complaints. In this case the passenger was an asthmatic MD.
(sorry if this was a little complicated)
