There is a specific faq item regarding Finn Edwards' passive ability as pertaining to Unique Assets, but I cannot make heads nor tails of it.
Q. What happens if Finn Edwards uses his passive ability to not discard a flipped Unique Asset when instructed?
A. After resolving the effects on the back of a Unique Asset, if the investigator was not instructed to “flip this card”, the Unique Asset is shuffled into the Unique Asset deck.
This occurs most frequently when Finn Edwards uses his passive ability to choose not to discard a Unique Asset, but it could occur in other ways. Regardless of how it occurs, the Unique Asset is shuffled into the Unique Asset deck.
First of all, my understanding of double-sided cards is that any time they are discarded, they are shuffled back into the deck (as mentioned under the Discarding section on page 5 of the Reference Guide). If this is the case, how is Finn "using" his passive ability doing anything other than what would normally happen anyway? If the answer is implying that he cannot use his passive ability to any positive result, then I would expect the answer to start by saying "Finn cannot use his passive ability to change the outcome etc."
I have read other comments suggesting that any item that is discarded is not done so technically as part of the item 'effect' so the discard doesn't fall under the power of Finn to affect it. The answer in the faq here still seems unclear to me. What is it saying?