I don't see how there could be anything wrong with leaving a patient in Triage, upon being told to do so by the receiving facility. Except we don't leave them unattended, on the stretcher. That's a lawsuit waiting to happen, suppose they try to get off, and it tips over? Screwed. "A high percentage" of the people who ride in on the stretcher, didn't need an ambulance-or a trip to the ER in the first place. Triage or fast track areas, for EMS, is a great way to metaphorically slap someone across the face that feels if they're in an ambulance, it will be considered an urgent matter, and they shall be whisked right in and taken care of before anyone else.
In a recent incident, as is common is rural areas, I was summoned to give aid via my home telephone. (I don't use the land line, I use a cell; and internet, etc., is through the cable line. So, when my phone rings; it's like 30% wrong number dialers and 70% "I need the ambulance".) I got there, gave first aid, then suggested they call their doctor the next day. Nope, "I think I'd get seen quicker if I went in the ambulance". No, you don't need an ambulance, in fact, you didn't need me to come all the way out here. They agreed, I left. An hour later, they called the ambulance. In transit, a call came in for a medical, in an area that takes more than an hour to access. I never make someone regret using the ambo, I WANTED TO, but I didn't say anything. I said in the radio report, "triage appropriate", and the person sat in the waiting room for six hours (according to them). They said "next time I'll complain of chest pain. Great, @$$#01e.