My coworker has been freaking out that our company doesn't do Agile or Scrum right and it will negatively impact his career. He claims that some elite company will want him to prove he worked in well oiled Agile machine. He also claims his last company had it down to a T yet he voluntarily left so they couldn't have been that damn spectacular.

I'm on my 7th company and no one does this shit "right", everyone makes it up. Also it's impossible to prove that you worked in a perfect environment to a different employer, if they even care at all. If someone asks, just tell them what they want to hear because no one actually works in this mythical world of Agile perfection.