If you do not use Bluetooth on the Apple TV yourself, you can probably disable it to prevent this from happening. Heck, I didn't even know BT was an option on the device.
It sure sounds like your neighbor was accessing your network. If you know him, I would politely ask Randy to check his phone to see which network he is attached to. At the very least, it will let him know you noticed his presence on your network.
I would also change my network password, as...