I think you have good insight into his behavior and the reasons behind it, especially how it might be part of a learned pattern from childhood, from his mother. I am glad that you seem to be able to deal with this with understanding and compassion, and so you can handle it calmly......
My husband will sometimes make sarcastic remarks (and he doesn't mean to be hurtful at all, doesn't always see that he is either, though of course it sure can be!), and I've tried to keep in my mind things I've learned about why he is what he is/says and does what he does and work on dealing with it calmly, responding rather than just reacting. Sometimes walking away is the best thing; sometimes just trying to say something in a calm way about how that comment hurt or asking why he said it helps, too.........responding in this way is something my T calls finding my voice (without sounding like a harpy!)