here in Central Europe batteries in the trash can are the cause for massive dumpster fires and explosions (not that often, but there was one just last month, took several days to extinguish the fire [0])

[0]: https://www.theinternational.at/nusdorf%E2%80%90debant-500-f...

This is not just a central europe problem. A bit further west people throw them in the trash as well. Fun and smelly since the garbage truck drivers usually notice it when driving and then dump all trash on the street.

Both will ultimately be true for a disturbing percentage.

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.