Hi Simple.
Gotta love them empiricist. They were the ones that came up with the concept that causality can not be linked to observations of events. More than 250 years ago. Just because I drop an anvil above my foot does not mean it will fall on my foot and break it. The two events are separate. I drop the anvil. My foot is broken by it. But I do not
know this will happen. I can only draw conclusions based on what happened before and what I know about gravity and mass and the fragility of my flesh and bone. I see the sun rise each morning and conclude it will rise tomorrow. I do not
know for a fact that it will. I am simply assuming it will rise as it does each day based on it's past performance. So technically you are correct. We can not
know anything except that we can not know everything.
But as others have pointed out it is superfulous to doubt evidence on the bases of our inablility to measure. If that were the case we would never learn anything. IMO.