i am against required help of police for the exact reasons demostrated and brought up. bystandards do not typically have a great deal of training, and may inadvertantly make things worse. or they may freeze up. or put themself at risk without any insurance.
I had the debate with a friend over the legality of this law (in the US at least). he argued that all American's have an inalienable right to life and therefore they cannot be force to risk it. Of course that popular phrase is actaully from the Declaration of Independance. My argument was for the 4th amendment argueing under "unreasonable seizure of person". he thought it may be under the 9th amendment -- if a right is not specifically enumerated it will not imply that the right is nullified. or somthing like that.
However, i would not want this to go to the supreme court. With the supreme court we've got, i'm not confident the constitution will be interpreted the same way I interpret it and further either vedict may have lasting negative results.