Old Trafford was rocking in the second half as United fans stuck with their team and, on the whole, under-fire Mourinho.
Rafael Benitez has won six of his last nine matches against Manchester United in all competitions (D1 L2), including two wins at Old Trafford in that time (4-1 in March 2009 with Liverpool, 1-0 in May 2013 with Chelsea).
The visitors' goals resulted from appalling defending from a United side that has looked weak in that department all season, both coming from Newcastle throw-ins which would have been dealt with by an organised defence.
"I think I'm furious", he said on Sky Sports after a lengthy pause.
Mourinho was speaking after United came from 2-0 down at half-time against Newcastle to win 3-2, thanks to Alexis Sanchez's 90th-minute header.
After talks over pasta and pizza, Mike Ashley told senior members of the squad, which included Jonjo Shelvey, Matt Ritchie and Jamaal Lascelles and manager Rafa Benitez his intentions for the club this season.
Manchester United have just 10 points from seven Premier League games this season - they last had fewer at this stage of a top-flight season back in 1989-90 (7 points).
The former World Cup victor has been heavily linked with a move to United as the pressure mounts on Jose Mourinho but his agent has moved to dampen that speculation.
"We can not upset, because we did so well for a while, and we deserved more". Where are the values at Manchester United?
Instead, he claimed the criticism was more of a problem for players who froze under the spotlight. We had chances in the first half to score a third goal, and chances in the second half too.
"Any manager would struggle at that football club with the way in which it is operated".
"As a team, we did so well", said Benitez. "If they play for the manager, they are not good professionals".
"The ones that read the papers, that are connected with social media, they thought maybe I had gone", said Mourinho.
The former Magpies left-back was part of "The Entertainers" era under Kevin Keegan in the mid-90s before returning to St James' Park between 2001 and 2006, finishing in the top five three times under the legendary purist Sir Bobby Robson.
"We are better than this and because we are better than this, our situation is going to improve".