"Is it THAT hard to understand?"
No but you are being very dense. An engineer can't become unqualified to be an engineer when he walks out of the office, nor can a doctor, nor can a lawyer, nor a plumber, nor a burger flipper. In fact, the professional bodies you refer to can take away their license but can not stop them from being qualified.
The woman IS a nurse, her education and experience doesn't disappear when she walks out of the office nor when she forms her opinion. Her legal obligation and liability for the consequences of sharing her opinion however should disappear insofar as it is no greater than anyone who could easily also have knowledge on a subject but doesn't get paid to employ that knowledge in their day job.
If I ask a doctor or lawyer friend their thoughts on something related to their profession at a party there is a very good chance I'll get a different answer than I would if I'd paid them for a consulation. I'm aware of their education yes, but they are not giving a professional response with all that entails, I'm a friend asking for their real opinion without the constraints of covering their ass professionally attached and also with the understanding they haven't had the opportunity to review the situation in full depth. Similarly, if I ask a friend who is a mechanic his thoughts on what I've seen happening with my car and a rough ballpark of what it would take to fix it, I don't expect that to carry the same weight as an actual inspection and quote. In a personal setting he might tell me the chances of something breaking are ridiculously low with very high costs and he wouldn't bother on his own vehicle, in a professional setting he might need to cover his rear and recommend fixing that same thing so he wouldn't be liable on the off chance this was the one time in a thousand something went wrong.
The personal opinion of someone who happens to be a professional is a different thing than the professional opinion of that same person.