"It was an error in judgment" is exactly the sort of thing I would use as a euphemism if what I meant was "she committed a crime but I don't think she's a bad person." And this is part of why I try not to judge people Good People or Bad People most of the time, but rather look at whether it was a good action or a bad action that they did.

I think a lot of us have people we would stand by if they committed a crime, especially if it was a financial crime rather than a violent crime. But I think it's crucial that "stand by" does not mean "cover for." You can love someone and be there for them every step of the way without covering for their misdeeds. And if you start thinking "I don't want other people to know how my significant other actually behaved," that is a giant red flag for the relationship and leads to really, really bad places.