What events are "testable"? Even a very simple event like flipping a coin has multiple outcomes. And will in fact produce different outcomes every time the event is tested. And the more complex the event, the more different outcomes it will produce. Flip the coin 10 times and record the outcomes. Flip it 10 more times and see if you get the same outcome. You almost certainly won't. Keep flipping it 10 times and see how many times you get a different result. A LOT!
Also, who and how was it decided that the event we need to "test" is about which side of a coin faces up after it has been flipped and landed? Oh, wait, that would be that subjective "I do". Who decides how the coin is being flipped? And how it stops flipping? And how many times it must be flipped and stopped to produce "objective evidence". Oh, wait, that would be that subjective "I do", again. And on and on it goes, with that subjective "I do" determining what the question is, what event exemplifies the question, what the parameters of the event is and how to isolate it from everything leading up to it and following it. And then how to test it, and how to interpret the various results ... You get the idea.
The whole scenario is rife with subjective decision-making from start to finish and yet we're supposed to assume that what results is the "objective truth"?
Not hardly.