bitjet: If your FIL still has that email and he's in the US, he can go to small claims court.  Or he can go to a higher court like ionstorm did.  He can definitely forward the email exchange as a PDF file to ionstorm, and ionstorm can include it as evidence in his ongoing BFL lawsuit.  Not sure if your FIL can add his case to ionstorm's though, to save on time and fees.