The Scot has described the decision of referee Lee Probert to book Hernandez for simulation as "an insult" after St James' Park stalemate
The Mexican went to ground under a challenge from former United youngster Danny Simpson in stoppage time but was booked by referee Lee Probert for simulation, a decision that Ferguson has described as an insult.
He told Sky Sports: "It was a clear penalty and it’s an insult because he has booked him.
"The referee has had a good game tonight, the referee’s had an excellent game but he lets himself down by booking the player. If he’s not giving a penalty then fine but to book him is an insult.
"I watched it myself and there was definite contact."
The hosts also had a penalty shout turned down in the second-half when Peter Lovenkrands was brought down under the attentions of Anderson on the edge of the United box, but the Scot has stated that he failed to see the incident.
"I haven’t seen that," Ferguson insisted. "I would have to see it again because I haven’t seen that."The Premier League leaders could have taken the lead through Ryan Giggs on the 68th minute but the Welshman fluffed a superb chance from only 10-yards out.
Speaking of the miss, Ferguson said: "It was a great chance but actually the defender has just got a touch on it just before it came to him, just a fraction to put him off a little bit.
"In the first 20 minutes Newcastle played very well. Full marks to them they did exceptionally well in the first 20 minutes but as we got to half time I was pretty sure we’d improve and we did really well in the second half.
"The passing was terrific, we got into great positions but we didn’t trouble the goalkeeper and that’s the only thing. We played really well in the second half."
When asked whether he saw the result as a point gained or two dropped, Ferguson admitted that Alan Pardew’s side had performed well but stated that he felt his side were comfortable for the majority of the game.
“With the way Newcastle fought and challenged," he added, "they will probably feel that they deserved a point, particularly the first 20 minutes but for the remainder of the game I felt we were more or less in control.
"At this stage of the season, we’re in a better position than we were in on Saturday, it’s one less game, we’re in the same position [as we were] with Arsenal and five games left.
"You’ve got to look at Chelsea also and how they respond, they’ve got three home games in a row now but there are two important games coming up now, that’s the Arsenal game away and the Chelsea game at home."
The 69-year-old also praised his players for bouncing back from their FA Cup semi-final defeat to Manchester City, stating that the physical effects of the clash weren't evident in his team.
"We tried our best to freshen up as best we could in terms of Saturday because Wembley can be a tiring pitch as we know," he added. "It’s a slow pitch and can drag people down a little bit but in fairness I don’t think we showed any of that tonight.
"They looked really energetic our players, they thrived on the challenge and that’s good to see at this stage of the season.Ferguson will return from a five game touchline ban on Saturday and responded positively when asked if he was relishing the prospect of returning to the dugout.
He said: “Absolutely. Mind you I think the staff want me to stay up there.”