Not quite the same, but once I was flying home LGW-MSP-LAX (on NW) and had been upgraded on the domestic leg. There was a huge line to get thru security/passport check -- I think this was just after the really started enforcing the one bag carry on rule.
Anyway, this official looking guy came out and said "Anybody holding a business or first class boarding pass come this way..." -- well I
was holding a first class boarding pass (just not out of London but he didn't ask that) so I went with him and jumped quite a bit of the line
