What should I have done?

Sounds like all is well, then.
But, yeah, you made the right call. He writes it and your job is to make it work the way you need it to work. In this instance, it was his oversight that created the situation in the first place.

 

Exactly. A lot of writers don't seem to understand how little time desk people have, especially at a smaller shop, when you're trying to fill 4 or 5 roles yourself. But if there wasn't time for a call (like usual), a quick e-mail saying, "Hey, letting you know this is what we're going with as the lead. Don't have time right now, but let's talk about this tomorrow." usually worked for me.
And after that, if they're still whining about it, then yeah, fuck em.