A Virgin Atlantic spokesman said it did not have a policy against passengers travelling in uniform. He added: ‘This was a completely isolated case in which our staff were incorrectly advised by a [G4S] security agent … We have made contact with the passenger in question to express our deep regret for any upset caused.
Wikipedia: G4S plc (formerly Group 4 Securicor) (LSE: GFS, OMX: G4S) is a British multinational security services company headquartered in Crawley, United Kingdom. It is the world's largest security company measured by revenues and has operations in around 125 countries. With over 657,000 employees, it is the world's third-largest private sector employer (after Wal-Mart Stores and Foxconn).
Apparently a security agent hired to serve Virgin Atlantic gave the airline employees bad information. At least that is what Virgin seems to be claiming.
Incidentally the apology issued by Virgin is in the next to last paragraph of the story which strikes me as odd. It should have been placed much higher and this leads me to believe the writer was attempting to slant the story into a most dramatic form.