Oh FGS of course she's not after him for his money, how ridiculously vulgar and misogynistic to spring to that idea immediately.
She just wants to improve his sartorial sense.
But to be serious, women are told all the time that domestic abusers aren't really responsible for their actions and that women provoke them, blah blah blah. He's probably spun her some line about how Nigella was a fucking provoking, difficult, stroppy cow who constantly pulled rank because of her family connections, put him down, was emotionally abusive to him and he was at the end of his tether, he knows it was wrong, he couldn't help it, he's never done anything like it before or since, it was a one off, etc. etc.
And he's charming, well educated, cultured, well-informed and very, very plausible.
Why on earth should she know better? She's someone who got famous because she's good with clothes, not because she's got a searing analysis of male violence and gender power differentials in relationships and society. Why shouldn't she believe the lies the man and our culture tells her?