
My indirect harm litmus test would fall along the lines of like an OSHA style philosophy of regulation, for example for any kind of ledges we generally require rigid hand railings. If someone got hurt falling off a ledge at my workplace sure I didn’t do anything to cause it, but I’d still be on the hook for their injury because I didn’t take the required steps to reasonably prevent unnecessary injury.
To use a real world example of anarchism in action, shopping carts in a parking lot. I’m doubtful anyone has said “you have to return your shopping cart to a cart return” but the generally people do return their shopping carts. There’s also people in vests that come around and clean up the parking lot of loose shopping carts. Sometimes people might offer to pass off a cart they just finished using to someone else, or maybe even snag and extra errant cart on their way to cart return. There’s no heirarchy, no authority on high dictating the rules, just people doing their thing and generally following the rules but there is someone who is paid to make sure things get cleaned up when the inevitability of stupidity happens.