Mason punched Lions prop Stuart Fielden after an altercation in the third minutes of the crunching encounter, leaving the British player nursing a broken nose.
The charge was made after Great Britain officially complained about the incident after the game, and Mason will face a judicial hearing on Monday with the possibility of his missing some of the remaining games.
Mason was also placed on report soon after for a late challenge on Sean long which left the half-back with a cut over his right eye but will escape further punishment after the challenge was deemed legitimate.
Initial reaction was that Mason could have been sent off after either of the incidents and had been fortunate to stay on the field.
But Great Britain coach Brian Noble refused to comment afterwards, saying: "That is test match football. It was very tough in the first 20 minutes. The officials will look at that and it is their decision now."