They looked to have all three points until Willy Boly was on hand to seize on a cross that dropped through Dubravka's hands at the back post.
Benitez said: "In England they don't understand the rules".
But in another interview, the Spanish tactician claimed: "I didn't like the challenge at the end". We have been here for years and it's still very hard to explain that.
Willy Boly's header earned a 1-1 draw against Newcastle on Monday and was the sixth goal Wolves have scored in stoppage time in all competitions this season.
Newcastle's record signing Miguel Almiron, the Paraguayan striker who joined from Major League Soccer side Atlanta United, gave the visiting fans plenty to cheer about as he made his debut.
'It is a bad way to concede.
Their opponents meanwhile are in scintillating form, winning their last three league games and scoring at least three in each one.
Benitez added: "I'm happy with the performance of the team, we were controlling but it's not easy".
Schar didn't play at Chelsea but has been excellent in the other four games, certainly Newcastle's man of the match against Cardiff and Tottenham, as well as being very good against Man City and Wolves.
Raul Jimenez and Diogo Jota were thwarted by Dubravka and Wolves sit seventh, two points ahead of Watford. "It feels just as good as a win sometimes when you level up in injury time", Ikeme tweeted.