Not funny at all. This was obviously a baby squirrel the man had rescued, maybe even bottle fed, and he was releasing it to live its life. Only to get killed by a cat who should never have been outside. I’d be very upset, too.
You do realize that squirrel is already on the menu of numerous predators including the native cat known as ‘Bob’... Grey foxes, red foxes, great horned owls, Redtail hawks, snakes, etc. And when it grows up it would dine on the eggs and chicks of birds with just as much enthusiasm as any cat. It’s what they do. They don’t just eat nuts.
When you release something into the wild, that means it’s now part of that system. Predators and prey. And who says cats should be kept inside a house all their lives?