Shawn repeatedly refers to the cat as "the little boy cat." The cat is calico, a color pattern that occurs only in females. The filmmakers were fully aware the cat was a female, however James Roday (Shawn) thought it would be funnier if the cat was thought to be male.
(at around 1 min) While Gus and Shawn are driving from the apartment, a large clock in flowers can be seen out of Gus' window. Seconds later the same clock can be seen outside Shawn's window. There is no indication that Gus is driving in a circle.
At the beginning of the episode, when Shawn and Gus are walking along with the street in the background, one can easily see a Vancouver tour bus drive by them. This is particularly notable because the back of the bus is emblazoned with a Royal Union Flag, the flag of the United Kingdom.