It added insult to injury.

This figure of speech describes something said or done that does not help a problem.  For example, if someone falls and hurts themselves and another person says to the first person, ‘You are clumsy’, that is adding insult to injury.

那是傷害之餘，又加羞辱！

有點像中文「傷口灑鹽」「落井下石」「幸災樂禍」「火上加油」之類的成語；明知對方受傷了，還當面說些風涼話，叫人很難堪；也是很不道德的行為。