Not sure of the exact details of this case, but prima facia,
it appears that the naughty nurse was posing as being qualified, when in fact, she was not.
The term "nurse" is protected in law, and the ability to check whether or not is registered, is straightforward enough Search the register | Nursing and Midwifery Council
The difficulty comes when the nurse is in fact registered, but tells porkies about what duties they are competent to perform.....so for example, I, myself, am highly competent, at, dealing with kids with fevers, but have never performed a smear test in my career.
The process relies on self reporting, and unfortunately the Governing Body (The NMC)
do not have sensitive enough measures to sort the goodies from the baddies.
The good news is, that the checks and measure in place to protect women undergoing smear tests, (she was probably picked up as a result of her failure rate) have prevented further damage.
Anyway, must dash, got some work to do....