Referee Mike Dean had a busy 90 minutes, brandishing eight yellow cards in total and also sending off Stephane Sessegnon for an apparent elbow on midfielder Cheik Tiote.
Of Tiote's reaction to the contact Sessegnon made with the Ivorian, O'Neill said: "Tiote, this 'hard-man' of the Premier League, has clutched part of his anatomy that wasn't even touched.
"He was hit between the chest and neck, enough to hit a fly over. He's gone down two-and-a-half seconds after the incident, and rolled around 14 times.
"We're still digesting what happened in the game and attempting to move on, but there were a few things that happened in the course of the game that we weren't too happy about."
Lee Cattermole was also handed his marching orders by Dean after the final whistle following a verbal exchange between the player and the official, and in the aftermath Pardew was critical of Sunderland's approach during the encounter.
O'Neill, though, has defended his team: "His [Pardew's] was an extraordinary analysis of the game. The half-time stats are a total contradiction to what their manager said. They've twice the number of bookings we have, and twice as many fouls.
"You think you've watched the game, given a reasonable analysis, then you hear the opposition manager saying Sunderland had a gameplan to upset them, to unnerve them, to basically - and he used the word ugly - attempt to kick them off the pitch. If there was any team attempting to intimidate it was Newcastle."