In order to know what’s going on with the remote particle, you have to observe it. And we know what that does, observation on its own causes ‘perturbations’. So I don’t think we’ll ever have solid proof of entanglement, because observation gets in the way, as it always does in Quantum Physics. Kinda think it was designed that way, myself.
If someone is observing you, does that mean that you do the opposite of what you were going to do ?