I think I'd point your instructor at the Concorde disaster. You have no way of knowing what's happened. A small fuel leak in the fan cowl that's lit up will be put out by the engine extinguishers, but your fire warning system cannot tell you that's all that's happened. It may be an uncontained failure of the turbine section; the engine cowls now have huge holes in them, burning fuel is now spreading over the wing, nothing's going to put that out. If you're a minute from landing, going around seems like madness!