Both sides were reduced to 13 men at stages in the second half with the game going to uncontested scrums when a prop from each side was shown yellow for not scrummaging straight.

Saints hooker Joe Gray was on the field for just four minutes before he was sin-binned for not rolling away from a tackle and yet there were no visible warnings for either side from Owens, who refereed at the last World Cup.

In the second half Owens sin-binned three players in three minutes with two of them being Saints front-row forwards.

Saints ran out of props and the game had to go to uncontested scrums until Gray reappeared.

Northampton, who at one point even had 13 men on the pitch when they should have had 14, survived the chaos to win 30-17, but the frenzy of cards spoiled a fast-flowing contest.

Mallinder said: "It did make the second half chaotic, you do lose the flow of the game really.

"I didn't actually think we had given away that many penalties before our sin-binnings, I wonder about that. To lose two props, it does affect the game."

Bristol had two players sin-binned before Gray went and then three minutes later Owen showed a yellow card to prop Ben Broster, on his Saints debut, and opposite prop Mark Irish after asking them to scrummage with their shoulders straight three times.

Then Owens insisted Bristol bring a prop on for another forward despite there being uncontested scrums.

Mallinder added: "It was hard enough for us to work out who to bring off and who to bring on, let alone the crowd.

"At one stage I think we were down to 13 men when we should have had 14 men on the field. It is hard enough for us to know what is going on, let alone the fans."