“Beings can’t hurt humans” was partly a bit of artificial-intelligence foreshadowing (see Asimov’s Three Laws of Robotics), partly one of the rules I needed in order to justify “every government and military in the world is not quaking in their boots over Beings and/or determined to Catch ‘Em All for the threat they pose to human beings.”
Bianca: You can’t want to turn him away now.
Sparrow: I thought you said Beings don’t get hurt!
Bianca: Yeah, well, obviously I was wrong!
Sparrow: That doesn’t make it our job to protect him! We can call a shelter, there’s got to be one in the area…
Bianca: What makes you think they’ll take him? They’re not designed to help non-human victims!
Sparrow: What, and we are?
If whatever beat him up decides to come for us next–
Spot: You should know that I can hear everything you’re saying.
Sparrow: First you lie, now you eavesdrop.
Bianca: Sparrow.
Spot: I ‘m trying to be honest now! It’s not my fault I have better hearing than you people! And you have nothing to worry about.
We don’t hurt humans. Beings can only harm other Beings. And humans can hurt us, but . . . Look, you’re not in any danger from what happened to me.
