I certainly agree the training was lightweight (metaphorically speaking) but we have several unknowns:
What was SAT at 410? If the atmosphere was considerably off ISA, the speed margin in the coffin corner might have vanished. Could a highly experienced crew have handled the situation on that day? Probably depends on instability in the atmosphere. These guys plainly ran out of margin.
The mere fact that the aircraft was cert. to FL410 DOES NOT mean that it is safe in any and all atmospheric conditions way up there.
Relight training was also probably lacking.