This is a common misconception about quantum mechanics. But if you look at the theory, the predictions depend only on the experimental setup, and are obtained entirely in a scheme that does not require my presence in the equations-- it only needs to me to see if I was right.
That is controlled by the experimental setup, not my presence.
That statement may or may not be correct depending on how certain key words are intepreted, but taken at face value it sounds like a common misconception about "delayed choice quantum erasure". Half the articles I see on that topic make steam come out of my ears, because I know they are feeding that false impression. Nothing that an experimental setup does later can alter the correct prediction of a prior outcome. It is only our interpretation of when things happen that tends to be faulty-- our intuition about causality, not causality itself.
Certainly there is nothing obvious about it. But the role of the observer in quantum mechanics is way oversold-- the real issue is the role of the observer in all of science. Science is manifestly an intellectual organization of the interaction between an observer and his/her environment, and that is as true in Newtonian mechanics as in quantum physics. It is only the people who mistake their science for "what is really happening" that run into philosophical conundrums, and not surprisingly-- logically, the use of a false premise will tend to do that.