When the children are setting up the stalls for earth day, Clyde Donovan says his father is a geologist, but in S03E02 "Spontaneous Combustion", the mayor says that Randy Marsh is the only geologist in South Park.
Phillip is holding the sword when he has yet to pick it up.
The voiceover on the "Behind the Blow" special on Terrance and Phillip says eight million people lost their lives in the 1999 U.S. and Canadian war. However, the war -- which took place in the "South Park" movie -- ended with Satan bringing everybody back to life, so nobody died. Except Kenny, who remained dead.