One of the things I absolutely fucking loathe on my MacBook is it will always turn on the Bluetooth upon hard (re)boot. I never use Bluetooth; I turn it off for a reason.
It literally does not matter what I tell the operating system to do: The tooth must blue, for that is the One Apple Way(tm).
Although that sounds annoying, clearly the reason for that behavior is this entire thread. If the old couple had not been zooming at the time, they would have rebooted and that would have fixed things.
If I had known that rebooting would re-enable Bluetooth, that would’ve been a good fix in this particular situation. Although I do see how it can be annoying under normal circumstances.