He claimed scrum-half Tom James should have been awarded a first half try and that Bedford’s final try should have been disallowed.
He said that the match DVD had confirmed his view during the game that the try-scoring pass was ‘two metres’ forward.
Griffiths was also fuming at the referee’s decision to allow Bedford to kick for goal after he had blown for time and the two teams had shaken hands.
“Apparently the fourth official said the kicking tee had been thrown on before Bedford kicked the ball out of play at the death,” said the Welshman.
“I’ve never seen anything like it! It didn’t affect the result but it cost us a losing bonus point which we deserved on the day.
“It was a match-winning performance against an in-form Bedford side holding down third place and playing at home.
“It was a tremendous team performance which is just what we (the coaching staff) had asked for following the home defeat against Richmond.
“Both sides scored four tries during the game and the only difference was the fact that they kicked three more penalties than we did.
“As I say, it was a tremendous team performance though there were players who were not on the top of their game and who made mistakes.”
Knights picked up another three injuries during the game and both hooker Dave Nelson (shoulder) and second-rower Matt Challinor (hamstring) look set to miss Friday’s B&I Cup quarter-final at Jersey. Josh Tyrell could also be a doubt with a back issue.