That makes sense. It is 'a baby step' at best, and the cruel calls are much tougher to detach from. But that is what we need, isn't it? To detach from the hate and anger of the other so we can see where truth may lay, what responsibilities we may need to own up to, and decide what to do next.
I AM NOT defending his ignorance on being a father, but when my W had her first pregnancy I asked about things that mattered to me. Those were not the same as what my W felt mattered. I also didn't feel the baby was alive yet. Remember, the baby lives on your life, not on the person outside of you. We can't feel the power of small movements, so it affects our hearts less.
A lot of movies show dads as all that, but let's face it, aside from us learning how to behave from others, we don't really get it. Having him come to the hospital, see his son or daughter's first breath...those are the goals. Those will make him either be absent or care.
His calls show a lot of anger, too. Anger at your lack of support (as he preceives it) and more. If I recall, his addiction wasn't street drugs, it was medications. They put a warning on the package for a reason...it happens to all sorts of people. That doesn't make it right, but I'm sure there's a whisper in his ear to blame you.
Makes sense about the work calls. Why not tell him / text him.
