Absolutely...Schiller began working for Trump as Director of Security in 2004. This is a major resignation of a long time Trump loyalist.

Here’s something whose timing is either a remarkable coincidence, or a sign that Donald Trump’s firing of James Comey was even more suspicious than previously known. Donald Trump hired his longtime personal bodyguard Keith Schiller to a White House security position, then used him to personally deliver the news to James Comey’s office that he’d been fired. Of course Comey wasn’t in his office, and was instead across the country in California that day, and Trump probably knew that. The move always stuck out as suspicious: why would anyone, even someone as whacked out as Trump, send his own bodyguard to deliver a firing letter to an FBI Director who wasn’t even there?

This does not mean that Keith Schiller did anything wrong or illegal himself. It’s possible that he’s seen the new revelation about the two firing letters, and he’s simply concluded that it’s too messy for him to want to remain in that role, or perhaps he’s now feeling like Trump used him.