Momoe
"you can't expect any certifying agency to look at this incident and somehow extrapolate that the battery design is suspect."
No, but there is a link which the FAA is aware of: the behaviour of the composite fuselage structure when exposed to extreme heat.
In the Laredo incident the fuselage insulating blankets caught fire, but the plane diverted quickly.
Boeing's battery "fix" allows the possibility of flying up to 3 hours with a very hot steel box under the floor. 1500 miles to the nearest firefighter.
Sure, the composite's fire resistance has been tested, but so were the batteries.