Crew Tracking knows "nothing" about your schedule, other than the trip you are on. He should of called Crew Tracking and told them that he had an APD the next day and couldn't do it.

I've done that, I was on reserve, on a trip where the plane broke. And Broke. And broke some more, so they extended us a day. But the next day was a Golden Day off, so after reading the contract I called Tracking and told them that. 1/2 hour later they called back and put me on the next DH back to my base. This was in SEA so there was 7Er coverage right there, but Tracking doesn't know what you're doing after the trip, whether it's APD, Vacation, Golden Day, etc.