My earlier line was clearly meant to draw the line at what is legal (hunting, fishing) and moral (killing for food when necessary) compared to this individual's actions (attempting to kill an inconvenient nuisance.) I did not claim that fishing or hunting were moral or kind. But they can be necessary. And there are accepted methods of dispatching with the prey that are generally followed by ethical hunters and anglers.
You can keep bringing your fishing analogy back into this, but the facts remain: licenced hunting and fishing are legal and regulated; unlicenced (attempted) killing of an animal out of frustration is not.
From a pure logistical perspective, if we allowed every home owner to kill every "pest" (and since it's in the city, what safe/acceptable methods could they use? who would regulate it? who would enforce it? the last thing we need is a wild west orgy of killing) there would be thousands of dead animals that would have to be disposed of. What would be the acceptable methods for doing carcass disposal? Who would be responsible for that? Furthermore, a void would be created in the ecosystem that would be filled by other "pests" and then there would be another round of killings. All because people don't want their gardens torn up? How does this make sense?
Animals are a part of the urban landscape and always will be. More importantly, they are a part of the ecosystem. If a homeowner doesn't want to be invaded, there are steps he or she are responsible to take - metal flashing on the roof, sealed porches, diligent upkeep, etc., not to mention other preventative measures - secure garbage, cayenne pepper, lighting, pets, etc. That is part of the "deal" when buying a house. Anyone who would try to eradicate every so-called pest in an effort to keep a pristine home and garden is an OCD psychopath, in my opinion. "Stuff" does not have a greater value than life.