Cockpit tampering?
The report in the Telegraph suggests that the satcom reboot implies some sort of mischief in the cockpit. Isolating all nonessential systems is also very close to the top of the 'smoke in the cabin' checklist. Communications with the ground give no indication as to why anyone would start executing that checklist, but it's probably something every wannabe pilot has tried in their simulator. Whether it was a real or perceived emergency or a ploy to clear the cockpit is a matter for speculation, but I would think the knowledge of (more or less) how to do it would be fairly common in the aviation community.