It would serve him right if he lost his job after how he treated his colleagues.

同僚をあんな風に扱った後だから、彼が仕事を失っても自業自得だ。

You left your umbrella at home? Well, that will serve you right for not checking the weather.

傘を家に忘れたの？まあ、天気を確認しなかったんだから、自業自得だね。