I assume you are referring to my post, @noworklifebalance @ColleenDonaghy? You are correct, noworklifebalance, there is always one... who doesn't read the full post...
I agree it is not appropriate for a PA with a PhD to use their title to imply that they are a medical doctor.
My post was referring to a PP's ridiculous suggestion (that I quoted) that the title Dr should be protected by law so only medical doctors can use it. Here's the relevant quote again:
I think doctor should become a protected titled used by only medical doctors
Medical doctor is already a protected title.
Dr is only a customary title for medical doctors without a PhD used in the UK and some other countries. Other countries use different titles for medical doctors.
Dr as title for people with a PhD or equivalent academic qualification is used internationally and has been long before medical doctors used the honorary title.
The PP thinks that the UK should stop academic doctors from using an internationally recognised title by law so only medical doctors can use it ie the people who are entitled to use it by virtue of their qualifications should stop using it because medical doctors use it as an a customary title. That would be somewhat ironic considering that, historically, because the title Dr for someone with a doctoral degree was not protected by law, the title was adopted by quacks with no qualifications... It also seems rather linguistically arrogant to claim the title for medical doctors in the UK because the word doctor has evolved to mean a physician in the English language because of this historical quirk when it actually means teacher in Latin 
I would also guess it's not even legally possible to protect a title used by 2 different groups.