The scene where Mr. Garrison writes down some maths problems occurred after recess. But later on he told the students to copy them down and solve them 'before recess'.
In the scene after Butters suggests starting an actual company he mentions a "Caitlin", however according to the chart behind him his "employees" are called Annie, Megan, Sally and Ashley.
By the time Yates arrested the pimp, he was doing nothing illegal as he was technically sleeping with his "wife" and not a prostitute.
Kanye West is seen when Butters goes to the pimp convention, so that means Kanye is still alive in the world of South Park.
The plot that states Butters has never kissed a girl is actually incorrect. Butters can be seen being kissed by Rebecca in the episode "Hooked on Monkey Fonics".
The song playing during the students party is Peaches - F**k the Pain Away.
Butters: Boy, Kyle was right, Sally! There's guys with kissing companies all over the country! (Butters reading off the computer) The person managing all the women is known as the pimp, while the working women are referred to as ho or bitch. Oh! (To Sally) You're a bitch, Sally!
Mr. Garrison: Butters, Butters do you have a problem?
Butters: All these bitches are kissing fellers and they haven't figured out they could be making some serious f***ing money!
-Latin America: March 1, 2010 on MTV Latinoamerica.