Even calling it tax evasion is a stretch, she had a complicated situation involving a trust set up for the house she had with her ex to insure her severely disabled son would be taken care of, then she claimed her new flat was her primary residence leading to a lower rate of stamp duty. She got some advice that said it was ok but was then told she should seek specialist legal advice to check that which she didnt and now has to pay back 40k.

Its not good, and she was right to step down, especially as housing minister, but its hardly a grievous sin.