Hammer left parts of the Japanese footage out of their version, you can see and hear the complete version as the director intended on the Japanese reel that is included as an extra.
akatanaka posted at cathoderaytube some insightful posts on this and here's a relevant excerpt-
"On close examination of the original Japanese reels of Dracula included on your Blu-Ray disc, there seems to be three shots within the climactic disintegration scene that are NOT included in your 2012 restoration.
Timing 33:21
Shot of Dracula’s shriveled skeletal hand wavering just above the floor.
Timing 33:23
Medium CU reaction shot of Dracula’s face grimacing.
Timing 33:42
SFX dummy head shot of Dracula with “normal†eyes instead of the less realistic backlit yellow eyes."
This missing reaction shot of Lee as he 'gives up ' right before he goes down is a serious screw up. I feel their limited budget is to blame, they did the best they could with their resources ( but sorry guys, it's a major missed effort, along with the questionable re grading of the color ). They are supposed to be doing THE MUMMY later this year and announced recently it was intended for 1.33 projection. When will these amateur 'new' hammerheads get a clue

They also failed to get the audio right at Lee's death scene , his final 'breath' is hardly heard on the 2012 Hammer restoration, listen to it as the chest collapses on the Japanese reels. So I am far from impressed with their ability to reinstate footage, and adding in alternate footage sounds troublesome & here seems a dubious choice ( especially as they have officially cocked up several of these Blu rays ).