Middlesbrough manager Neil Warnock called Cardiff's equaliser "a disgrace" after he was denied a winning return to the Welsh capital in a 1-1 Sky Bet Championship draw.
Sheyi Ojo bundled home a 70th-minute leveller with Boro convinced that referee Jon Brooks had missed George Saville, their first-half scorer, being blocked off at a corner.
"I'm disappointed with the goal as it's an obvious foul," said Warnock, who left Cardiff last November after three years in charge.
"They've blocked Saville to give Kieffer Moore a free header. Referees at this level should be able to see things like that.
"It's a disgrace really after last Saturday's offside that wasn't offside. That's four points we've thrown away this week with decisions.
"I'm disappointed because I thought we did enough to win it."
Veteran boss Warnock won a record eighth promotion during his time at Cardiff.
The Bluebirds went up to the Premier League in 2018, but Warnock's team were often criticised for their direct approach.
"I was told they'd changed style since I'd left," Warnock said. "I'm not sure the style of football has changed if I'm honest.
"They're the best physical side and the towel's round the side with every throw-in.
"It was weird getting off the bus and seeing one or two staff when I was there.
"I had three great years here with (chairman) Mehmet Dalman, who was fantastic.
"I'll come back even when I retire to watch a game. I'll have a walk round and thank them, they were amazing to me.
"But life goes on, it was the right time for me to leave. I'd done everything I could."
Boro have gone six Sky Bet Championship games unbeaten since an opening-day defeat at Watford and Warnock has certainly made them harder to beat.
Cardiff have been impressive on the road – winning two of their three away games – but have yet to win at home this season.
"We have to make sure we are a little more streetwise," said Cardiff manager Neil Harris.
"The first goal mentality, we've got it away from home. We've had it for 12 months away from home.
"The majority of the time we have had it at home as well. But all of a sudden, we've got key moments going against us at home.
"Ultimately, they've come from set-pieces or giving the ball away cheaply.
"Bournemouth scored a good goal against us, I've got no problem with that.
"But the other five goals we have conceded in the league at home, three of them have been from set-pieces and two have been from us giving the ball away at the edge of our own box
"You can say it's unlucky, but you get to the stage where it's not acceptable."
