Best definition of medical emergency I've seen.

I've struggled and searched for a definition of 'emergency' before because the definition can be 'stretched' for convenience in hospital settings.
Emergency Services: Any health care service provided to a member after the sudden onset of a medical condition that manifests itself by acute symptoms of sufficient severity or severe pain, such that a prudent layperson, who possesses an average knowledge of health and medicine, could reasonably expect the absence of immediate medical attention to result in i) placing the health of the member, or, with respect to a pregnant member, the health of her unborn child, i) in serious jeopardy; ii) serious impairment to bodily functions; or iii) serious dysfunction of any bodily organ or part.
-from a provider contract with Coventry.
However, I'm not sure in this definition why it can't be an expert opinion rather than a layperson that would expect the adverse outcome. For instance, brainstem herniation is life-threatening but looks like sleepiness to a layperson.
-Tom.