I don't care what my airlines policy is I wont risk my life to save a wheel chair bound passenger. If I can get them off with an acceptable risk to my self then I will, but I wont be putting myself into harms way.
Having read the article I think the crew did the right thing. The fire service will not get on the aircraft if they think people are still evacuating from the slides, as they have to cut them off and put a ladder against the aircraft. My thinking would be to get off the aircraft, tell the fire service that a wheelchair passenger is seated in row X and cannot evacuate. then leave it to them, they have the breathing equipment and the training to deal with it.