I took mine to an Office Depot that "recycled the battery" for free. The guy at the register printed a receipt for having taken it, then took it from me and walked back into the administrative office by the front of the store. I assume it was to take it home. At least I tried...
Places like Staples and Office Depot have actual electronics/battery recycling bins they keep in the back. They aren't in front for anyone to drop stuff in because they limit what they will accept. So not sure why you're assuming he would take it home. I mean it's not impossible but I'd assume he was just putting it in their electronics recycling.