I don't think the wire strike idea is valid - he descends instead of climbs which requires a major lowering of the lever when you pitch that much nose up. I wonder if he was looking so hard for the LS that he suddenly realised the buildings were there, scared himself avoiding them and then tried a very difficult repositioning manoeuvre resulting in settling with power/incipient vortex ring into the LS. Any control malfunction causing the pitch up would not have allowed him to recover it and any TR malfunction would have caused a much higher rate of yaw.
The only other possibility I can see would be if he inadvertantly (or santa did it for him) selected the hydraulics off - this makes the Gazelle much more interesting to fly, causes a pitch nose up in forward flight and makes the yaw control (especially applying right pedal) very difficult. The lever also tends towrds mid position (about 8 degrees) which would account for the descent in the flare.