I'm sorry this happened - horrid for you both.
Sorry, but what you've done in your original post is choose to identify one aspect of the thieving scum's identity and associate that aspect with 'thieving scum'. It's not ok because you are, in effect, suggesting that Eastern Europeans are, generally, thieving scum.
How to make sense of why you didn't write 'thieving white/black scum' 'thieving male scum' thieving young/old/middle age scum?
If you imagine I'm from Eastern Europe, a decent human being getting on with my life and I read your post tile - I'm likely to feel that lots of people think I'm thieving scum because I'm from Eastern Europe.
imagine that you're English, living in Spain, and an English person does this to someone in a carpark, and you read your local diy forum with a post title 'Thieving English Scum' - I don't think that's going to feel fair or just to you.
I really don't want to have a go at you, particularly as what happened was a nasty heartless assault, dressed up in a sickening display of apparent concern, but ironically if we start labeling groups of people in negative ways we do actually make it easier for people to justify treating each other like ****.
Anyway good wishes and sorry your wife had this happen.