I'm damned if...

前文是说话人（Henry）在谈女的（She）在宴会上种种出格的举动，但是She's always got away with things.（运气不错，总是能逢凶化吉，逃脱惩罚）。She和Henry是亲戚关系，Henry因她无视传统的行为而担心她。女的年纪在60上下。

然后是Henry的一段独白：
She put deadly enemies next to each other. She ran riot over the colour question. And instead of setting everyone at loggerheads, I'm damned if she didn't get away with it.

这个And instead of setting everyone at loggerheads, I'm damned if she didn't get away with it.怎么理解？加上前面有Instead of...，似乎是几个否定了。