Evil Emperor
Taller Than Stalin
No. No it doesn't. I have built an electric circuit with defined physical characteristics, and they are proved science fact, it's been written up and accepted by the scientific community. You may as well say "you can't prove an amplifier makes things louder". Yes I can. Set up the test gear, turn the volume dial, coo look it gets louder, my decibel meter proves it. I can't prove the brakes on my car work? Yes I can, I take it to an MoT station and a trained, approved technician uses established known-science testing and a rolling road to demonstrate that they work, and he dishes out a pass certificate. That's proof. There is no collateral damage, except to bad science and false claims.
No, it's more like making the claim that two similar amplifiers sound different to one another. The first part of the ruling points to ABX testing to substantiate the claims made about mains-borne RFI. AFAIK, the claims you are ascribing to these filters have not been ABX tested (irrespective of other objective tests made, the ASA ruling is specific on this) and therefore would be rejected pending more substantial tests.
So no, no get-out clause.