After making such a massive impression in the first month of the season, and claiming the number one goalkeeping berth with England, Hart has suddenly shown signs of vulnerability.
The 24-year-old had a shaky 10-minute spell for his country in Switzerland last week and then got into a real tangle with Kolo Toure to present Nikola Kalinic with a tap-in.
As the player who had a far better view of the dangers that were lurking, Hart knows he should have taken control of the situation.
And he accepts the blame for the calamity lies with him.
"I got there and Kolo was about to head it. He heard me coming and left it," Hart told mcfc.co.uk.
"It was me getting in the way. I hold my hands up. I am sorry for that."
It is thought Hart will be taken out of the firing line for Thursday's Europa League group clash with Red Bull Salzburg in Austria, although he should be back for the Premier League trip to Wigan on Sunday.
"Defensively we feel as though we have made a decent start to the season," he said.
"We have still conceded only one goal from open play and that was a pretty freaky one."
With only one point from two games since the impressive win over Liverpool last month, City need to shake themselves from their slumbers pretty quickly.
Manager Roberto Mancini is expected to have Nigel de Jong and Gareth Barry back in his midfield on Thursday, when Wayne Bridge could also make his comeback from a broken foot.