Many states have Good Samaritan laws to a) protect people who try to help and b) require any trained people who happen to walk by to help.
When my husband was a security guard in the Philly burbs, another guard had this argument with management. A formal policy came down from headquarters stating "call for help; do not attempt to assist yourself." PA had a Good Samaritan law... and the guard was a trained EMT! There were other guards with Red Cross certifications in CPR, First Aid, etc... and according to company policy, they had to "call the professionals" and stand there and possibly watch people die, which they'd got those certifications to avoid. Yes, they should take a second to call 911. Yes, they should make sure the doors are unlocked so the paramedics can get in. But odds are they can do more good trying to help the person than they can standing outside waving at the ambulance as it pulls up!
Not to mention that ambulance response time is 5-15 minutes... by the time the professionals get there, they may be just hauling a corpse to the morgue.
http://www.webmd.com/heart-disease/n...hard-push-fast