^^ I am afraid that even official reports are pointing to that cause. One of the pilots for whatever reason including a possible suicide or terrorist act decided to cut the fuel lines - first one and then the other - right at the moment in which it is more critical and dangerous to do so.

Cutting the fuel is nearly impossible to be done by accident The switches need to be pulled and the switched so that it cannot be done by a casual inadverted push. After the lines are cut-off, even if they are put back into the right position, the engine has already lost the momentum and it is nearly impossible to bring it back in time to avoid the accident.

So...yes, someone in the cockpit decided to crash the plane, knew how to do it and did it in a way that nobody could have then prevented the crash.