That's just bullshit.
Also, given the state of medical research methodology, you could just as well argue that it would yield even more unreliable studies, each adding confusion to our knowledge.
Let's say that each research study spends 10% of its time on recruitment and another 5-10% of its time on compliance. (Real numbers can be much higher).
Open medical data would reduce both these efforts, so every study, regardless of quality now goes more quickly and/or is less expensive. This is the primary benefit.
Now you're pointing out that extremely open data can lead to rapid and perhaps erroneous analysis. This is true, but it would also lead to rapid and accurate analysis. My point is that everything speeds up and compliance regulations around data handling are far less impactful on study quality than are protocols around experiment design.
I believe open medical data would have absolutely zero effect on the amount of time spent on recruitment.
Source: Me. I work with clinical trials data management in a medical research institution pulling hospital-side clinical data and patient schedules into systems on the research-side specifically for the purpose of recruitment.
Please trust the opinions of people who have tried to do this work. There are many people trying to advance medical research in good faith who can attest to the insane inefficiencies of working with medical data.
Skip the essay but at least give me three or four sentences why I should feel differently?