Quote [parabellum]:
"The FMC is very useful for an established route, SID or approach but don't get mesmerised by what may or may not have been entered into the FMC, in this case, quite possible that from 01.19 the rest of the flight was conducted in FLCH and HDG Select."
While the maneuvers after IGARI are probably indicative of the plane being under control and being flown in an evasive manner, the sudden altitude changescould indicate the plane was not fully under control (?). If the plane ended in the far southern reaches of the Indian Ocean could that indicate an attempted return to KL by a pilot in an incapacitated state who then passed out after setting HDG? Just asking.