Legally, he's supposed to turn over the space junk to the owners, and he doesn't want to fight SpaceX, especially if they are being polite and provide a healthy donation to the Ituna skating rink as he requested.
But it's totally unclear if Canada has any laws on the books that could be actually used to compel a Canadian citizen to hand over a piece of space junk to a company in another country. So, from a space law standpoint, it would be a lot more "fun" if he refused. What would happen?