Luka Milivojevic stepped up to earn his side a point by sending the ball past Karl Darlow, but Benitez has questioned referee Andre Marriner's potentially game-changing decision 10 minutes into the second half.
"Scoring the second goal could change everything," he told Sky Sports News. "We didn't do it and we conceded what I would say is a soft penalty because he was pushing my player and my player was pulling. That changed everything because obviously they had more confidence and they were pushing and we know they have very good players up front.
"We had to be strong in defence and it was difficult. To come here and to get a point, before the game I would say no, but after the second half maybe. But I still feel in the first half we could have scored the second goal. The difference between the push and the pull? It's easy for the referee and the linesman to watch for that.
"It's something we have talked about in the past, but it has happened so we have to ensure it doesn't happen again in the future. We cannot do it, but I see a lot of penalties not given for us in every game. Different situations, but the same consequences at the end."
No Premier League side has conceded more penalties than Newcastle this season, with Sunday afternoon's the sixth awarded against them.