One has to question the logic of the chopper doing circuits, landing "two-thirds" down the runway. I suspect his final flight path would be very high relative to the 208 when checking final/lining up through their wing, and almost impossible to see.
Also, the CAGRO didn't pipe up when the 208 started to enter the runway? They are not ATC but that shouldn't stop them broadcasting a hazard if they see one developing.
Otherwise, hampster wheel...