Prophet, after watching the track file I observed the following.
The second hind that you hit did kill the pilot, the hind itself was still flying as per it's previous flight path before the vikhr hit.. Seen this lots and can even happen to yourself where the pilot(yourself) is killed but the KA50 fly's along it's route like nothing happened. :)
As for the hind flying through the mountains.. bug is all i can say.. This isn't a common occurrence, i have seen many AI helo still fly with no pilot but they do exploded on impact with the ground..