Exactly...it's also not reasonable to be asked to prove a negative. "Prove it's safe" (equivalent to "prove there isn't any danger") is "prove there isn't a teapot orbiting Venus" territory.
Every procedure has some negligible risk, and doctors are trained to mitigate major risks to peoples' health with screenings, medications and surgeries that are of lesser risk than the alternative of inaction. "Safe" is a reasonable explanation for the vast majority of laymen they have to communicate with.
My point is not that you must prove it safe. My point is that it is dangerous to communicate to people that something is safe, and simply assume that they understand that negatives can’t be proven, and you don’t literally mean that someone has proven it to be safe.
This is pretty much how we get into the territory of "this product may contain peanuts" even if it has never even been near peanuts, but that warning is need because if in the offcase it has touched peanuts the company can't be sued. But this makes pretty much every other warning worthless.
We shouldn't have to clarify that everything is only 99.999% safe and assume that everything carries some form of risk even if small.
By that standards everything we do is unsafe. Every single activity we do carry some neglible risk. Explaining all of these would be lot more trouble than value in general.
Every procedure has some negligible risk, and doctors are trained to mitigate major risks to peoples' health with screenings, medications and surgeries that are of lesser risk than the alternative of inaction. "Safe" is a reasonable explanation for the vast majority of laymen they have to communicate with.