If it was wild cat then yeah that's how nature works, but a domestic cat...nah. You can't have your cat going around eating shit unless you don't feed it and let it get its own food.
Come on guys.... Domestic or not, Natural habitat or not, It's fuckin' nature and that shit happens. Get over it. That squirrel's mom just watched its baby get taken away. Bet she won't let her kids out anymore. You have to put it in perspective...our big ass planet does not give a fuck about what some insignificant squirrel felt like. All that matters now is that she learned something and the species is that much more likely to survive.
I'd hardly consider domestic cats to be an "introduced species" in that habitat. It's not like his boa constrictor went out and decimated some animal population. People have owned house cats for centuries - and almost every single suburban/urban area has these domesticated cats wandering around killing for pleasure. The eco-system isn't going to crumble to do a few squirrel deaths.
I kill squirrels quite often... and rabbits... and deer... and whatever else is in season. Oh noes I'm a murderer!
house cats are pretty shitty animals for the environment My dad is a biologist and has always preached about how bad cats are, something he learned in college from his professor Archie Carr who ended every lecture with "go kill a cat" or "go kill an armadillo" as both cats and armadillos are exotic species to Florida Cats hunt only to kill, which is why they are so destructive as they do not get filled up since they don't eat their prey After our neighbors with cats moved away a few years ago all our animals that before were struggling ie snakes, rabbits, skinks, birds are now doing much better