Fer was expected to give the ball back to Cardiff from a 94th-minute throw in given after the visiting team had put the ball out of play at Carrow Road, but the Dutchman inadvertently rolled the ball into the net with keeper David Marshall out of his goal.
Rather than award the goal, though, referee Mike Jones ordered Norwich to retake the thrown in - much to the disgust of the home supporters.
This controversy came at the end of a match was lit up by the heroics of Marshall.
The 28-year-old - who played for Norwich between 2007 and 2009 - produced a string of fine saves in his first outing against his former club to deny the home team its second Premier League home win of the season on Saturday.
Jonny Howson and Leroy Fer went closest to breaking the deadlock for the home side in the first half but could not find a way past Scotland international Marshall.
His opposite number - John Ruddy - was rarely tested as Malky Mackay’s men struggled to create chances, but, when they did, the 27-year-old made an excellent save from Jordan Mutch.
The goalless draw sees both sides end a run of two consecutive defeats in the Premier League, but leaves Norwich in the bottom three with eight points from nine matches.
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