Question on a detail: It's not necessary to have deniability on the fact that you did wipe your device, just on the fact that you did it after you entered the border? Or said differently, if he'd wiped the device before entering the border, it'd be all fine?
(That of course only takes down the "physically impossible" part.)
I do believe that yes, if it was wiped before entering, there would be no charges (unless there was a shadow docket open... that gets murky)