I disagree again. For the stable or questionable patient, spending a little time on scene is understandable, especially if at a SNF where being able to mine the chart for a few minutes can be helpful.
For the acutely unstable patient not in arrest, I don't see why the EMT crew should be doing anything more than getting a report, slapping on a NRB, and moving towards the ambulance. The lack of treatment options limits the utility of any on-scene assessment once the decision is made that the patient is critical.
Ehh, I don't know. The stable patient requires nothing other than a set or 2 of vitals, decent HPI, brief screening physical exam, and transport. More of them are likely to be ambulatory, which can save a lot of time. Minding the chart on scene for a patient from some place that provides a chart is unlikely to be useful and can wait for transport or until at the receiving facility. The sick patient still needs some sort of HPI and physical exam (even it just lung sounds) on scene and brief assessment of vital signs (even if just eyeballing respiratory rate and assessing the pulse). And then there may be an intervention, whether placing on O2, or bagging or assisting with a med (e.g. epi-pen, NTG, or MDI). When bagging is needed or a med that you can give or help give, I think it would be poor form to just slap on a NRB and then move to the ambulance (which can actually be quite time consuming).
Overall, sick or not sick, I imagine the difference of scene time probably doesn't need to vary more than 5 minutes or so (with cardiac arrest being the exception).