The fire extinguisher is not just for show
question: why? the people appear stable; can they be "transferred" to the waiting room, with a report given to the triage nurse? You are tying up a BLS resource babysitting a patient, who might be waiting for hours, who doesn't need monitoring. They want to be seen in the ER; ERs have told people for years that patients are see in order of priority, not order of arrival, and EMS shouldn't let you cut the line. Can't you use your clinical judgement that the patient won't benefit from having EMS babysit them?
Let's not forget, once you are on hospital property, the hospital is responsible for patient care, not EMS.