MACH082.
The 777-300 has a tailskid whose very design is to absorb the impact. If the tail crushes this and hits the fuselage it triggers an EICAS. If it doesn't, then the it has done precisely as designed, prevents the fuselage from striking the surface, and it is safe to continue the flight. Exactly as per Boeing instructions and checklist design.
And exactly what the crew did correctly here. This has been proven by the inspection of the aircraft in Singapore.
It seems that you think you are smarter than the thousands of Boeing engineers who designed the aircraft. Here is your problem: they have been proven right, and you have been proven wrong.
You have displayed arrogance and ignorance; a very scary pair of traits for any pilot.
