My concern would be that the investigation in this case is more likely to be biased towards a system failure. Disgracing a major flag carrier is something very few regulars have the independence and courage to get away with.
What the bbc says is truncated and omits the info about the failing part, so people can point towards murder suicide because they don't have all the info.
Which is why you should always read avherald first...
The fuel cutoff switches are of a similar design to the 737 and most other Boeing aircraft. A failure in that design seems less likely than the most charitable explanation, that the copilot inadvertently went into the wrong mode of muscle memory.
The interim report does mention the SIAB NM-18-33. If you read that document it specifically says that the fuel cut-offs were installed with the locking feature deactivated on some 737 aircraft. It's a pretty big leap to that causing this incident. Someone or some thing would still need to have touched the switches to move them.
... which is more than the bbc one paragraph news item does?
Air India was government owned company till 2020s when it was sold back to the TATA group from whom it was originally nationalized from in the 1960s.
Stakeholders like regulators, employees individually could have different PoV or interests in the change .
Regulatory leadership could just as easily want to prove why this de nationalization was bad if so inclined as they could be for not wanting embarrass the flag carrier.
So it would be hard to categorically say that regulator has vested interest in protecting the flag carrier