it's obvious that he is not going to play "fair"....don't have the expectation that his family will either....he has gone to them for validation of his behavior...he feels that smearing you will build him up...and you can pity him because it is all he has right now.
He is the big loser here, he lost his family, his wife and his comfy home life...he & his parents/brother may blame you for years...it's the only way he can justify his own downslide...because he certainly won't blame his drinking will he?
I went through a lot of the same thing....i've been divorced for 23 years and my former BIL will STILL harp on certain topics...REALLY....they cannot get over themselves...i had the misfortune to open an email from my former BIL (my daughter gave him my address) when my Xhusband died suddenly...it was surreal....once was enough, i immediately blocked the address.