The words 'responsibility' and 'alcoholic' don't really go together. So I'd never get so frustrated or surprised that an alcoholic lies for any reason.
Sounds like he was more of an avoider than a pathological liar but there are lots of sober people that tell all kinds of 'white lies' to get out of situations they don't want to be in, and they do this their entire adult life. And it isn't gender specific.
Maybe thats just who he is, a weasel!