It is odd that he didn't answer the phone, BUT in my experience men don't answer their phones very well anyway. Or they might be somewhere where they don't have service and don't even look at their phone to notice it. So, I can see why you would worry, but I don't know that this is solid proof of misbehavior.
All I can say is that, if he cannot talk to you about these things, then what kind of relationship do you truly have to begin with? He really needs to understand that you have to be able to recover from his addiction as well, and that him being shady doesn't help you to be able to focus on you. Just my thoughts.