Could you please explain what this is? I don't know what it is.
One problem runs into a whole bunch of problems one after the other.
The 777 is a fly by wire design. Essentially, a robot. Software mediates all control signals to the control surfaces, ie., servos do all the work. Even thrust is managed by computer.
A rolling system collapse would be some event that cause most circuits to eventually end up disabled.
Could also been them running a checklist for a fire, and they were overcome before they completed reset of breakers for various systems.
These are general ideas, not specific. But the gist being, I do not believe any disablement was a part of a nefarious plot. It was disaster recovery or disaster progressing.
Given the ping times, and the skill of the pilot, the pilot might have actually settled the plane on the water, and then it eventually sunk.