It's left unexplained how Beaver transports the 20 pound monkey home (let alone its large cage, which weighs even more) from its previous owner. Later in the episode Beaver erroneously wants to send it to South America (to 'retire' in the jungle there); Macaque monkeys are native to Asia and Africa.
When Stanley goes missing and it's supposedly pouring rain outside, the sidewalk is bone dry and there are shadows on the yard.