Neil Warnock looked across at West Ham manager Manuel Pellegrini from the away technical area and shouted: “How are we losing 3-0 to you lot?”
Three goals in 12 minutes midway through the second half condemned the Bluebirds to a 3-1 Premier League defeat.
For almost an hour Cardiff looked a solid unit capable of competing with their hosts at London Stadium, but they let themselves down a crucial times.
Joe Ralls missed a first half penalty which would have given City belief and momentum, while West Ham scored their first goal after Sean Morrison and Joe Bennett got in each others way.
All three West Ham goals came courtesy of mistakes with substitute Lucas Perez scoring twice and Michaill Antonio once.
Perez had not scored a League goal in 700 days, but he struck with the quality of a clinical marksman.
“I still don’t know how we lost the game, let alone 3-1,” said Warnock. “When I called over to Manuel he said ‘I don’t know’.
“You have to put penalties away. The crowd were just about to turn and then we make it easy for them with three goals in 12 minutes. After that they don’t have to worry about a system or anything.
“Victor (Camarasa) wanted to take the penalty and he will have the next one.
“I was more pleased than I was against Everton. We are hanging in there. I can’t fault them for effort.
“We haven’t got enough in the squad; we need two or three extras. It’s a long season and we need to help some of the lads that need a breather now and then.”
Now Cardiff turn to their home match against Southampton, who play Spurs at Wembley Stadium this evening.
That’s a huge match against a Saints team currently two points behind City.
Warnock has a lot of thinking to do this week before deciding on his line-up for Saturday’s clash.
Bruno Manga could move to centre-back with Lee Peltier going in, while Josh Murphy and Bobby Decordova-Reid carry potent threats. Murphy’s wing play with Decordova-Reid playing behind a centre-forward would pose problems for Southampton.
Manga and Sean Morrison could link at the heart of defence with Sol Bamba operating in a midfield role just ahead of the back four.
City were on the back foot for most of the game against West Ham, who had 76 per cent possession in the first 20 minutes, but there were still clear signs that Cardiff have the heart and spirit to fight on.
They have the joint worst away record in the Premier League and must put that right quickly. They have three more road games this month.
A Marko Arnautovic foul on Junior Hoilett gave Cardiff their penalty, but a poorly struck shot was saved by goalkeeper Lukasz Fabianski diving to his left. That is a third successive penalty save by Fabianski.
West Ham manager Manuel Pellegrini said: “In the second half we improved, with better movement, and played the ball into space and into feet and players marked man-to-man.
“It would be more pleasing if we kept a clean sheet.”
West Ham United: Fabianski, Masuaku, Rice, Ogbonna, Diop, Snodgrass (Diangana 75), Noble, Antonio, Anderson, Chicarito (Carroll 63), Arnautovic (Pérez 40). Subs Not Used: Adrián, Balbuena, Zabaleta, Obiang.
Referee: Graham Scott