PFP backed out on Marz 48

[3beejay3]

On Sunday, the PFP backed out all on its own on my left fork during a ride. It actually backed out farther than it's supposed to be able to & ended up allowing a buch of oil to escape.

Has this ever happened to anyone else? Any ideas what caused it? If so how do we address it? (it's currently at my service guy)
(I did a couple searches, but couldn't find anthing, though I though I read on here a while back where someone else had this happen)