Need a help in helicopter crash accident (top urgent)

Hi,

THIS IS TOP URGENT!..

I have a movie with a helicopter accident. The helicopter crew claims
that the
reason of the accident was a damage on the tail rotor blade. My brother
was a
copilot in crew of that helicopter and I don't have any reasons to
don't believe him and his colleagues. But investigators claim that it
was basically overloading and helicopter was crashed by this reason.

There were some eye-witnesses that saw when helicopter was in hovering
one piece of the tail rotor blade was broke away. After that the crew
worked only for saving lives of passengers and saving machine. But
after questioning by investigators eye-witnesses ceased to remember
this important detail.

Would you help me and the crew of that helicopter?

The tail rotor has 8 rounds per second and the movie has 30 frames per
second.
The blades of tail rotor are invisible on the movie.

1. Is it possible to see blades enough to make a decision on the exact
reason of damage. like on this http://www.helis.com/movies/bige005.mpg
2. Is there any other technique which can be helpful to solve this
problem using exist movie.

Sincerely,
Rustam Bogubaev