Puzzle: IRV gets it wrong

Clay Shentrup wants to know an argument that instant runoff voting (IRV) gets the winner wrong in at least one of these two elections:

#voters their vote
------- ----------
8       B>A>C
5       C>B>A
4       A>C>B
(winner = C)

#voters their vote
------- ----------
4       B>A>C
6       C>B>A
5       A>C>B
2       B>C>A
(winner = C)

Answer

Rename A→Z, C→Y, B→X in election #2:

#voters their vote
------- ----------
5       Z>Y>X
4       X>Z>Y
6       Y>X>Z
2       X>Y>Z
(winner = Y)

Rename A→X, B→Y, C→Z in election #1:

#voters their vote
------- ----------
5       Z>Y>X
4       X>Z>Y
8       Y>X>Z
(winner = Z)

Now the sole difference between the two elections is 2 "Y>X>Z" voters switched their vote to "X>Y>Z" causing Z to stop winning and Y to start winning (?!).


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