It seems that borders at corners are a common issue. Take a look at the CA\NV\OR tri-state marker. The one from the first survey in 1872 is a pile of rocks with a wooden post sticking out. It is also the legal marker thanks to a Supreme Court decision in 1980.
[
commons.wikimedia.org]
There are something like 20+ other markers in the surrounding 10 acres of land. As I recall the Von Schmidt marker is incorrect but not off by very much at all.
Susanville before the first official survey of the Nevada border would claim to be in CA if NV territory tax collectors arrived and claim to be in NV when the CA tax collectors were there. They would go so far as to change the flag in front of the courthouse depending on who was in town.