The conversation as it probably actually happened:

AC guy: You got the flashing?
Roofing guy: Yeah, we've got the flashing.

The conversation as it SHOULD have happened:

AC guy: You got the flashing for the hole we need to cut in the roof?
Roofing guy: What flashing that you need, what hole?
AC guy: Well you see, we're going to have to cut a 14" diameter hole in the roof for the duct and we need flashing for it.
Roofing guy: Oh, well that's a custom flashing, we'll have to have that fabricated specially for this job, let me get that started now, so that when it's time for us to do the job, we'll have it all ready.
AC guy: OK, great, we'll see you then.
Roofing guy: OK.

And that's just the latest. But can you see the finger pointing going on now, as neither company can finish the job because of two stupid pieces of flashing?!?