McManaman clattered knee-high into Massadio Haidara, who was subsequently carried off on a stretcher with suspected ligament damage, but the youngster escaped punishment in the first half of the Latics' vital 2-1 win.
The 20-year-old's challenge provoked anger from the Newcastle bench at half-time with assistant manager John Carver being sent to the stands - along with Wigan coach Graham Barrow - after twice trying to confront McManaman in an ugly melee.
To add insult to considerable injury, Arouna Kone's 90th-minute winner - after Davide Santon had cancelled out Jean Beausejour's first-half opener for the hosts - appeared to come off Maynor Figueroa's hand in the build-up.
"It is an awful challenge. The pictures speak for themselves," said Pardew. "I thought it was a bad challenge and I was 60 yards from the incident.
"The players knew because they were on top of it and there was a lot of bad feeling about that incident when it goes unpunished.
"He (Halsey) said 'If I've missed it I apologise' - that was at half-time.
"If it goes unpunished it doubles the impact on the mentality of the players and the team and it did have an impact on us, you can't get away from that.
"My job was to calm the players at half-time, not go looking for retribution, and try to win the second half - which to all intents and purposes we did.
"But again there's a decision at the end where we should have had a corner, it goes up the other end and there's a handball - that is tough to take. The linesman is looking right at it, the referee is there and all our players reacted and in that split second we didn't clear the ball - that's what happens when you miss a decision as big as that."
- Sports & Recreation