This gentleman, on Trash Island, collects trash for treasure.
However, it seems the script is designed to grab anything in the inventory with "trash" in the name.
So as well as the bundle of trash I was trying to give him, he sucked up two druidic ritual items (Druidic Crystal of Trash Island), as well as another hard to acquire, very expensive spoiler item with "trash" in the title.
I am just glad I didn't have DM loot with "trash" in the title, even though that is the usual quality of DM loot my characters deserve...
Confirmed. He failed to pick up my Bundle of Trash (possibly as it was named Bundle of Rubbish or something?) and picked up my Trash Tribe Drums from the quest I just did.