In Flight Safetys video you can actually see the nose rising when the spoilers deploy.
Yes, believe can see weight coming back off nosegear. My goodness what a nasty thing to cope with floating back up after a heavy intial contact.
What a heavily compromised aircraft this is: once you start having to 'tweak' all manner of aerod.& stability systems for cruise-drag reduction, it is very easy to start chasing your tail to regain low-speed handling. In this case, and IMHO, the large pitch inertia makes this
even more awkward.
The propensity to roll-over is probably augmented by the relatively high CoG, with an inertial axis that slopes down from aft fwds. This itself can increase maingear loads when out-of-line.
It may well have all been out of the crew's hands after the initial touchdown, which state will become apparent only with FDR.
Very upset that Japanese news clip is showing just the second touchdown (repeatedly!)... very ghoulish! I can only imagine what is going through FedeX minds right now... both pilots & management.