"落井下石"用英語怎麼說？

“落井下石”，漢語成語，意思是看見人要掉進陷阱裡，不伸手救他，反而又扔下石頭（drop stones on somebody who has fallen into a well）；比喻乘人有危難時加以陷害。與英語習語“kick/hit/strike a person when he is down”意思相近。

例句：

我終是無法做到在吉米倒黴時落井下石。

In the end I just couldn't kick Jimmy when he was down.