Most EMTs carry jewelry saws in their emergency vehicles for precisely this purpose. Also, carbide rings can be cracked.
Our ring cutters have carbide blades, not much use on carbide rings. Just how do you crack a carbide ring without injuring the finger? This is a real question because it is only a matter of time before I will have to do it.
OK, I googled it and see there are instructions on cracking a carbide ring. I just need to buy a vice grip to leave at work and hope that the technique works when I try it.
I heard about another emergency room that had a deal with a local dentist who would cut off the rings with his diamond drill.