United striker Javier Hernandez was booked for simulation after going over Simpson's outstretched leg in injury time as Newcastle clung on.
"It was a clear penalty," he said. "It's an insult because he's booked him.
"I thought the referee had a good game tonight, but he's let himself down by booking the player.
"If it's not a penalty, fine, but to book him is an insult. There is definitely contact, no doubt about that."
Asked about the incident that saw Peter Lovenkrands tumble under Anderson's challenge in the second half, Ferguson claimed not to have seen the tackle.
"I would have to see it again," he said.
With the Gunners having also dropped points this weekend, Ferguson could be happy with a draw.
"At this stage of the season, you look at it and we're in a better position than we were on Saturday," he said.
Newcastle defender Danny Simpson insisted the referee got the Hernandez penalty claim decision right.
"To be honest, I didn't feel like I touched him, maybe he went over too soft," Simpson said on Sky Sports. "I'll have to look at the tapes, but I'm glad the referee gave it my way."
Asked if Lee Probert got the decision right, Simpson said: "I didn't feel (contact) at the time.
"I'm glad the referee made the right decision and the lads got a point having worked so hard."
Newcastle manager Alan Pardew admitted Simpson was playing with fire in making the challenge, but insisted the referee got it right, while claiming Newcastle had a far stronger penalty claim also turned down.
"Danny sticks a leg out, which is dangerous, but he didn't touch the guy, he definitely dived and was looking for it," Pardew said on Sky Sports 1. "I'd like to praise the referee, he was very brave there. United are pushing at the end, looking for a late goal and history, so there's pressure there."
Asked about the incident that saw Lovenkrands tumble under Anderson's challenge, he said: "The Lovenkrands one was a sitter.
"It was a story of two penalties, one that definitely was for us, and one that wasn't for them."
Newcastle have moved up to ninth, reaching the psychologically important 40-point barrier that should see them safe from relegation. However, Pardew said there would be not let up from his players.
"I think we owe it to ourselves and to the rest of the league that we put in a full performance (at Blackpool) on Saturday," he said. "I think with the commitment we've shown tonight, the points we've got, the goals we've got, we're pretty much safe but we want to finish high and put in the same commitment and effort as we have tonight against the probable champions."
