FYL. Welcome to reality. Get back on that horse, because it's only gonna get worse.

You should never do that! Now that I've been on the other side of the process a few times, I've noticed that a few finalists are clearly better than the crowd, but are very similar to each other. At that point, it's practically a random chance. It could come down to the person supporting you is less aggressive than another hiring committee member who is supporting someone else. Congrats on getting that far, but I'm sorry it didn't go your way. This is why we don't let other leads get cold.

My experience with jobs and interviews is to never rely on an existing relationship or friendship to get a job. Yes, that’s plus. But if you back off on putting your best foot forward because you think you have the inside track you could be badly disappointed. Sometimes that other person doesn’t have the authority to hire or recommend your hiring. Sometimes they aren’t as positive on you as you think. It’s not over until you get the actual offer in writing with a human signature on it… It usually takes a lot of applications and several interviews until you actually get an offer. You have to keep plugging along both at your current job and at the job seeking until you have a real offer that is acceptable to you. That’s a double workload in a way, but it’s worth it in the long run.