I don't really know how to describe this or know if anyone else is experienceing this but here it goes.
I recently did an account to account chracter transfer, the toon I transfered was a BH.
After the character transfer was completed I decided to respec the toon I transferred to another proffession.
After the respec I still had my 1st professions skills plus my new professions skills.
My origonal profession was BH I respec'd to Medic. I now have BH + Medic skills. Apparently no matter what I now respec to I still always have my origonal professions skills.
Image of me wearing BH armor with my profession screen open showing I'm a CL90 Medic.
Screenshot of my skills window showing medic & BH skills.