Luckily, I have been able to watch this several times. Due only to the lack of responses, or anyone with knowledge on this one, I will have a GUESS:
Pilot is flying a Serbian Army Gazelle. He is delivering Santa for the Serbian Orthodox Christmas into an LZ in an urban area. As described above, all apears fine and beaut until the pilot attempts to fly between two buildings, at about 30 odd knots and maybe 100 ft. Just as he is about to dissappear behind the building from the camera's view , the aircraft enters a rapid pitch up manoeuvre and we lose sight of him. Very shortly after, he comes back into view heading back the way he came, and looking stable, but there are some small jerky movements. Suddenly, it looks as if control is lost, the aircraft begins spinning, rolling, and descending into the trees.
As the turn is left, it would suggest some sort of tailrotor issue, but there also appears to be some roll to the right (perhaps a reaction to the spin). The coning angle does not change sufficiently before impact to imagine that engine power has been completely lost, although things are happening quickly at this point.
I reckon he has gone to fly between the buildings, and seen a wire (hence the rapid pitch up), and then attempted to fly back out but had suffered a wire or object strike to the tail, and/or possibly the main rotor. Damage causes loss of control, and aircraft smacks in.
The tail rotor cannot be seen in the post crash footage, but there doesnt seem to be any obvious cables or similar around the main rotor head which is visible. The pitch change links do look damaged, but that maybe as a result of the 100 ft of pine trees they had to cut through to get to the ground. Both the pilot and the crewman are then filmed being attended to by medical personnel on the scene, and they dont look too critical initially, which is good.
Oh, and you can tell all your kiddies to relax. Santa walked away in need of a barber, a new set of shorts, and another reindeer team.
