If these helicopters are FAR Part 135 they'd likely have TCAS. Glass cockpit helicopters flown by commercial pilots are quite likely safer than driving.
Also, a skilled pilot can autorotate a Bell 407 without damage or injury. In fact, it would be easier than ditching a A320.
A friend of mine had a near mid-air in a Bell 407 over a city, flying between buildings, due to the other helicopter operating on an IFR clearance below authorized IFR altitude, shortly after takeoff. Luckily, this particular Bell 407 had EVS(Enhanced Vision System) FLIR (Forward Looking InfraRed) and they were able to descend hard and passed under "IFR" helicopter. The FAA busted the other pilot for failing to set their transponder correctly, and failing to maintain proper lookout, among other things.
Oh nice, I didn't realize TCAS was available there.
As for autorotation, my worry isn't so much the procedure (although it sounds much trickier than a gliding landing in an airplane) but the fact that you don't get much horizontal maneuvering and there aren't many good places to land in a dense city, and the fact that there are many single points of failure that make it much more likely to happen.
Also, a skilled pilot can autorotate a Bell 407 without damage or injury. In fact, it would be easier than ditching a A320.
A friend of mine had a near mid-air in a Bell 407 over a city, flying between buildings, due to the other helicopter operating on an IFR clearance below authorized IFR altitude, shortly after takeoff. Luckily, this particular Bell 407 had EVS(Enhanced Vision System) FLIR (Forward Looking InfraRed) and they were able to descend hard and passed under "IFR" helicopter. The FAA busted the other pilot for failing to set their transponder correctly, and failing to maintain proper lookout, among other things.