Interestingly, if you right click on the video in the first post then click on "Watch on Youtube" there are several other video clips of B747s landing at NRT in similar conditions and all the spoilers deploy on landing. I wonder why the difference.
Oh and before anyone launches in and tries to explain to me how it all works I should mention that I have over 25 years experience flying Boeing airliners of various sizes so I have a fair idea.
For example,
Regards,
BH.