When you observe someone acting in a way that seems obviously against their self-interest, it is always worth considering the possibility that there's some interest you don't understand...but it's also worth considering the possibility that they're doing a bad job of considering their own interests.
They assumed they were going to win, and thus enact punishment for questioning their authority.
Most "rational actor" theories of human behavior actually only work in the large (where the average can dominate outlier behavior) and in systems where rational action is a positive feedback loop ("a fool and his money are soon parted").
If those assumptions break down (especially the second, i.e. if foolish use of money results in more money accruing, not less), what we perceive as rational behavior should not be expected.