This is where you are making your faulty leap of logic. You argument of ignorance. Which is assuming that since it has not been proven to be true, it must be false. You completely forget the third option of, we just do not have enough evidence to support either proving or disproving the statement.
There is no "undecided" option. There is not a lack of evidence. We have a running collection of evidence. The primary source making the claim has failed to provide any evidence to back that claim. This is evidence that the claim is false.
If you want to cast doubt on the claim that the satellite was adequate source for determining gravity variations, you can't make the claim that the satellite was not shielded. You need to make the claim that "Since we do not know if the satellite was properly shielded, we cannot assume the accuracy of the experiment."
I really don't understand how you are not understanding this.
It's very simple. The primary source claiming that the satellite was shielded has not provided evidence of
that claim. From our experience we also find an absence of evidence.
If the only evidence we have is that is does not exist the conclusion must be, necessarily, that it does not exist. Until evidence is presented otherwise, this is the current truth.
We cannot say with honesty "there may be no evidence of ghosts, but we cannot assume that ghosts don't exist". The evidence is that ghosts do not exist, and that is the conclusion.