787 is correct. It liiked like a telephone cable was cut by the S 76 tail rotor.
The A-Star pilot hit his own longline. The sudden stoppage of the main rotor blade causes a massive lateral jolt and out of balance condition that broke the tail boom and pilots seat. I've seen similar accidents that boke the pilots neck as well.
Arguably, cables are the number one or number two cause of fatal accidents in helicopters, depending on how you group the accidents.