Leupold Alumina scope caps

Yesterday I was out hunting and at some stage while carrying gun via sling over shoulder the Alumina scope cap on the eye piece end of the scope has jumped off! :pissed off: How the hell did that happen?! I made sure the caps were tight before I went hunting but somehow it has managed to completely unthread it self :wtfsmilie: .
Anyone ever had this happen? Seems unusual.
So now I'm on the lookout for an eyepiece-end-of-the-scope Alumina cap.. Hopefully someone has a spare one lying round so I don't have to get a pair :thumbsup:

Yes I have lost a couple now, no longer bother with the rear one, get expensive