PD's have sometimes started eating a wounded PD even before it has died. If you kill a female PD with pups, the pups are eaten by the other PD's.
PD's are nasty little cannibals, and closely related to rats. Killing a few PD's just adds some protein to the other PD's diet.
According to guy, his barrel is 3.1 meters long and his air pressure is about 15 BAR.
If he shot those rats with something like my BSA Lonestar .25, he would not have so many rats running away. My Lonestar kills PD's much better than his .22 cal kills those rats. If shooting rats that big, moving up to .25 cal would be a good idea.
Letting the coyote go would raise a few eyebrows around here. Coyote hides are also worth money, while rat skins are not.