So if I was her, I would have asked to get a written confirmation of this upgrade pledge from 'mgr Paulo'.
Seriously, what a drama for something that happened 20 years ago. Also, pretty typical "ma fan" locals attitude from Mrs. Chung of requesting something that goes way beyond 'returning the favor'. I mean, seriously, the entire family??? For some probably minor medical help offered?
So according to your theory, you're one of the ma fan people who are smart enough to second guess Mr. Chung's decision for not materialising the offer in advance.
Btw while I'm not trying to advise how big the favour should be but I really hope you know when CPR should be done during an emergency. It's for saving lives and it's not something like minor medical help.