I may be the outlier here then but ive never had any trouble accessing copies of my medical information either dental or cardio, and ive had a lot of cardio in the past few years. I dont bother asking at the time but instead write to the respective data controllers or patient liason teams and ask them for a complete copy of my records, emails, images etc. So far ive had success with each interaction seeing me receive a copy of my records as requested; no question as to ownership or license. Ive even been provided with viewing software for the MRI data. Now none of this answers the question who owns the copyright; just highlights I think you hit on someone who didnt want to do an extra step and got a lot of fluff responses in return.