(More detailed look [with letters changed])
| #voters | Their Vote |
|---|---|
| 8 | B>C>A |
| 6 | C>A>B |
| 5 | A>B>C |
In this 19-voter IRV election (containing, for those who care, a "Condorcet cycle") the winner is B.
But if the six C>A>B voters insincerely switch to A>C>B ("betraying their favorite" C) then the "lesser evil" A becomes the winner under all these voting systems (and is the Condorcet-winner), which in their view is a better election result.
Lying paid. The betrayal worked.