In the mid 60s the only helicopter I flew with a shoulder harness was the FH 1100, the Bell 47 & 206 just had a lap belt. After a fatal accident, CASA made all helicopters have a 4 point harness, even the Bell 47. The S76 came out with a 5 point harness. In all cases the lap belt should be tight low down on the lap, then the shoulder harness clicked in. In the photo that harness would not be too helpful.
Changing subject, I'm very surprised there is no mention of radio calls made by either pilot. If the first one had a mechanical problem or in cloud unexpectedly, you would have expected a radio call. I don't know how far away the second pilot was, the report seems to suggest he was following, in which case you would expect him to see or hear or say something to the other pilot. Then the second one returned which suggests conditions weren't the best. The final result was a tragedy for the 5 on board but also I expect traumatic for those following.
I hope they come up quickly with the cause to make sure it's not repeated.