Boss Martin O'Neill refused to criticise referee Lee Mason after Dwight Gayle denied Nottingham Forest victory at West Brom.
The striker went down easily under pressure from Alexander Milosevic and Yohan Benalouane to earn a penalty two minutes from time and allow Jay Rodriguez to rescue a 2-2 draw.
Gayle could face a retrospective ban for simulation if the Football Association investigate the incident.
Last season Omar Niasse was banned for two games after diving to win a penalty for Everton against Crystal Palace.
O'Neill said: "I spoke to the referee, he said it if it was a mistake it was an honest one and I accept that.
"It certainly looked like a dive, I've seen it back twice from a rather long lens angle and not on TV but everyone I have spoken to says it was a dive.
"In this day and age, it's very difficult for a referee, harder than it's ever been.
"It would have been great to have won the game, away from home against a side looking for automatic promotion."
Stefan Johansen's own goal and Ryan Yates' second-half strike had twice put Forest ahead either side of Jacob Murphy's goal at The Hawthorns.
But Forest were denied a vital win and they sit ninth, five points behind the Sky Bet Championship top six instead of two.
Johansen turned in Yates' close range effort after six minutes and stuttering Albion took until the 54th minute to level.
Newcastle loanee Murphy scored his first Baggies goal, driving in after Rodriguez had blocked Mason Holgate's drive.
Yates' first Forest goal put the visitors back ahead before Rodriguez saved Albion, who remain fourth, from the spot.
Boss Darren Moore said: "In real time it looked a penalty, once I look back at it I'll be able to give my opinion on it. It's earned us a point. The way the boys kept going was the most pleasing thing for me.
"The referee was in the perfect position and he's given the penalty, we have to trust what the referee has seen at the time. In the heat of the moment he's got a closer view than I had.
"I'm delighted with the point because the performance was lethargic. It wasn't just one or two, it was the whole team. Maybe it's just the volume of games. We just weren't quite on it."
