Well worth your time to read this article: Culture of Silence. Written by an ED physician about his perception that paramedics are not interested in and hostile to feedback.
Next read thoughtful responses from Chief Skip Kirkwood on the Firegeezer blog and Dave Konig on the Social Medic blog.
I imagine there will be more responses from EMS and I will add links to those responses here.
Bob Sullivan writes, A Culture of Silence is a Two Way Street.