TCAS --- in this environment, it would be calling TRAFFIC TRAFFIC every couple of minutes, which would drive you nuts, likewise but less so, departure calls, but that's the job, and handled well in places like Vagas where in the old days 7 or 8 helicopters depart at the same time, for Grand Canyon tours and the like, and is probably happening again.
Surviving pilot ---- what an amazing job that person did given the circumstances, and the damage, to get that aircraft down safely, many pilots have crashed under less strenuous conditions
ATSB --- I don't know the age of the EC130's but don't they all have in cockpit video camera?
Lets not forget we are all human; a monentary lapse; looking in to the sun, a distraction from a passanger, "Hey my doors open" "Hey I'm going to puke" "Hey I left my camera on the helicopters step" "My phone just fell under your controls"