Touchdown seems to occur at about 0:25 (jolt and noise) and almost simultaneously the thrust reverser sleeve appears to move but only by a very small amount (look carefully - the join gap noticeably widens). Unable to get the thrust reverser to deploy fully?
At about 0:36 that small gap closes again (re-selecting forward idle?) until 0:41 where the reverser begins to deploy fully. Visually, I get the distinct impression there was a jam in the reverser sleeve and the crew may have been struggling with it? As already mentioned, there does seem to be a delay between full visual deployment and audible spool-up.
Merely my opinion though!