David Hussey and wicketkeeper Bilal Shafayat, standing in for the injured Chris Read, combined to run out South African big-hitter Albie Morkel for four.
Then, Benkenstein pulled Pattinson to deep square leg and Alex Hales held the catch, but staggered backwards over the rope and threw the ball back into play before regaining his balance to complete the catch.
After much deliberation, Benkenstein took it upon himself to accept Hales' word that he was still inside the rope when he threw the ball up.
Nottinghamshire director of cricket Mick Newell told BBC Radio Nottingham: "I definitely thought it was out and I think the reaction of the Durham players around the boundary would confirm that.
"Dale Benkenstein asked Alex Hales if it was out and Alex said he definitely caught it and, credit to Dale, he accepted his word on that.
"We've known Dale a number of years and he's an excellent cricketer and a good fellow."
BBC Newcastle's Martin Emmerson: "Dale Benkenstein is one of the most honest cricketers you will meet.
"It was difficult to say whether Alex Hales had taken a clean catch to dismiss Benkenstein, but all the suggestions were he stepped off the pitch.
"Umpire John Steele wanted to signal a six but the Notts players were insistent that it was a catch.
"Replays suggest it was a six but Benkenstein took Hales at his word and walked."
Durham's Dale Benkenstein tells BBC Newcastle: "I waited for the umpires to confer and they said they were not sure.
"I asked the fielder and he said he was 100% sure he caught it, so I went on his word and walked. I feel it was the right thing to do.
"I didn't want to cost Durham the game but it's pretty disappointing when you look a guy in the eye and ask him if he was sure.
"If he said he wasn't that sure then obviously I would have stayed, but he said to me he was 100% sure and that was good enough for me."
Bookmark with:
What are these?