The most important thing you wrote was this "I was out having a good time when he called". Yep - that's GALing. Way to go!
Now, you have to completely ignore the fact that he called. It could have been ANYTHING - a friendly hello, a booty call or a misdial. As you say - if it is important - he will call back. Don't read anything into it. What you might do, though, is remind yourself WHY you broke up. That way, you don't slip and fall right back into it if he did want to patch things up.
Moving forward on your own is so much more courageous than taking the easy way out like so many people do. Like hooking up with Mr Wrong because it feels "safe". I like how you are handling things.
