They're lazy.
I use Google Apps for personal, family members. Google asked a few times if I'm sure I'm not a business. I said I'm not.
In the end, without asking anymore they stopped billing VAT because I'm a business. Well... OK.
Knowingly profiting from crimes is still illegal, so you might be liable, too.
If you can’t prove that you told Google that you are a private person using a business account, you might end up having to repay and end up with a fine.