Airbus says: PNF selects the FLAPS lever position and replies " FLAPS ONE"after checking the blue number on the ECAM flaps indicator to confirm the correct selection has been made.
To my mind this is a non event if the flaps position indicator went blue before speed reached VFE.
Hence the VMO/MMO changes to the next relevant one as soon as the indicator colours in blue.
Furthermore, your coworker would get an overspeed.
If he did not... Well he can complain.