FWIW.... I flew tours in Hawaii for 7 years albeit not on Oahu.
It apears to me that he is making a normal approach to a Helipad----a helipad that is not normally used by tour helicopters.Therefore it would indicate he "may" have had reason to fly there.... i.e. some sort of problem.
On final approach, something happens that causes the helicopter to descend rapidly.... this is NOT "settling with power".
Listen to the sounds.....
My educated guess is some sort of shaft failure or governor failure.