The suggested failure modes still don't fully add up. The fan would have been producing a leisurely five or six tons or so of thrust, which wouldn't have troubled anything compared to the previous take-off loads, so this isn't an overload failure.
If the LP drive shaft end had failed first, say from fatigue, there would not have been such a clean failure of all the fasteners on the LP compressor drive flange. The flange is pretty well undamaged apart from secondary impacts. And if the failure had been caused by all its fasteners being unsecured and falling out one by one, you would expect the final ones to have ovalised their holes. Which I can't see.