It is of course tragic that four people have lost their lives and there will be many families affected by this. My condolances to all, however (as a non rotorhead) lets not get carried away blaming the car driver.
I'm afraid that this type of accident was just waiting to happen. The only odd thing is that it hasn't happend before. The way any helicopter is allowed to operate in the US amazes me - I've seen R22s for example, approach and depart landing sites over crowds of 1000s of people.
The FAA would have made better use of their time looking at real flight safety issues such as this, rather than worrying about BA747s on three engines or whether Joe Bloggs from Southend doing his PPL stateside was a terrorist threat. After all, they ask you on the visa waiver form if you are a terrorist.