With my daughter, she was in the process of both the Presidential and the Congressional. She completed the interview and of course the application process with our Congress member. She was awarded the Presidential nomination just days after she had her interview. They said since they confirmed her Presidential nomination, they wanted to make it so another applicant had an opportunity to get her "spot" - which in my mind meant she had earned both.
But, as many of us here know, so long as you meet the requirements and get the appointment, it is all good!