Re: Easy solution
The problem is that Hypoxia is a sneaky bastard.
A typical sign of hypoxia is that you start thinking that everything is great.
Typical symptoms are singing out loud and giggling away because everything is funny.
Often it is the wingman that detects the hypoxia first (slurred speech etc). There are numerous accounts of wingmen having to work hard to convince the victim of hypoxia to do something about the problem (fly lower). -There are also enough accounts of the affected aircraft just suddenly doing a wingover and heading straight down to terra-firma.
I suspect that this is one of those failure-chain situations where more data are needed to find the root cause.
While hypoxia will not occur at lower altitude, the system failure might, and added sensor data can then help to solve the problem. Flight testing is all about finding the UGH-known.