I would disagree with the "in front of her face" with the recorder. I understand the deterrent. But frankly(no pun), I think it would just give FIB's W the idea to go out and get her own recorder and record EVERYTHING he says. Then head out to the editing studio and Tada! Here comes the circumstantial evidence.
Now FIB can't even speak about his kids for fear of what it might be turned into. Nope. Keep the recording covert, and definitely check it out through the L. In fact, if the L is that good and it is legal, why didn't she suggest it?? Makes me wonder about the legality of it. Best checked out before using it.