If "Daisy" knows that "Michael" had a Denibian Slime stone cross because he talked about it, but she had never seen it, and LE had said "We're trying to match this Denibian Slime stone cross with someone." Then "Daisy" might think to contact LE. But LE didn't. They just show a cross, and don't say what it is made of. So perhaps posters thinks "Hey, if we identify that wood, then people might think of a conversation with someone regarding having a cross made with XXXX type of wood, even if they never actually saw the cross."
Makes sense in my mind, because I had a NPD friend who would brag about having some BIZARRE things, but I never saw any of them (I suspect he didn't actually own those items, but you never know). So if an Ironwood Unicorn was part of a murder, I might remember he said he had one, but I would never have SEEN it.