It seems highly unlikely that even a senior and highly experienced nurse could carry out all the emergency procedures that might be required in an Accident and Emergency department. (Apart from anything else, I think a person who could do this would have the sort of nerves of steel and lack of conscience characteristic of a psychopath - and JW's character isn't portrayed in that way).
I know there have been examples of people masquerading as doctors but were they working in acute, emergency situations?
Also, why would a person resort to such a drastic solution? Given that she was already in deep water, wouldn't it make much more sense to go back to the reporter and help him to expose what was happening?
(I did quite enjoy it though - not quite sure why).