You're not that guy, that's perfectly fair.
I'm trying to find more information. Here's the issue, without the EPO, there'd be no legal basis for forcing Chris to leave that day.
I do agree though, on thinking about it further, that they probably did not issue it in advance. It would make it more likely that it was an officer-requested immediate EPO. This is provided for under § 19.2-152.8
EDIT: To clarify, there is always a magistrate on duty. The officer calls the magistrate and gets the EPO issued -- this can be done extremely quickly.
EDIT 2: The EPO is for three days, but if the officer feels the victim can't speak for themselves because of mental impairment, he can ask for an immediate three day extension, for a total of six days.