The Blues' title bid was dented as Fabio Borini converted a late penalty after Cesar Azpilicueta tackled Jozy Altidore in the area.
There did appear to be contact between the players and referee Mike Dean pointed to the spot. Mourinho, though, appeared frustrated by Dean's performance throughout, before also seemingly criticising referees' chief Mike Riley in a short and curt post-match interview with Sky Sports.
"I just want to say four things and I'm sorry because if you ask me more questions I'll repeat exactly the same thing," said Mourinho, who had not spoken at his previous three press conference following his fine for entering the pitch during a defeat at Aston Villa last month.
"Congratulations to my players because they gave what they have and what they don't have. Congratulations to Sunderland, because they won.
"Congratulations to Mike Dean because he made a fantastic performance and congratulations to Mike Riley, because what they did during the season was fantastic for the way the championship is going. Congratulations to all of them and I have nothing more to say."
Blunders from veteran goalkeeper Mark Schwarzer and full-back Azpilicueta handed Liverpool control in the title race. Schwarzer marred his league debut for Chelsea, with Petr Cech suffering a virus, by gifting Sunderland striker Connor Wickham his third goal in a week.
Full-back Azpilicueta then upended Altidore to hand Borini the penalty that secured a 2-1 success, with Chelsea incensed by a host of refereeing decisions and coach Rui Faria sent to the stands.
Mourinho had to drag Faria away from fourth official Phil Dowd as the hosts' protests turned ugly after Sunderland took a late lead.
Chelsea's defeat means leaders Liverpool can open up a five-point advantage over the second- placed Blues with victory at Norwich today.
Basement club Sunderland climbed within one point of 19th-placed Fulham, following up their 2-2 midweek draw at Manchester City with another impressive result on the road.
Samuel Eto'o's 14th goal of the season proved fruitless for Chelsea, with midfielder Ramires facing a premature end to his campaign if he is punished for appearing to strike Sunderland's Sebastian Larsson in the face.
The FA's disciplinary department will be likely to review footage of the incident, and can impose sanctions given referee Dean took no action during the match. Ramires' two red cards this season could see him receive a five-match ban.