With the game locked at 0-0 heading into the closing stages, Fer gathered a throw-in from Ricky van Wolfswinkel and rolled the ball into the net.
Cardiff were left incensed as goalkeeper David Marshall had put the ball out for Canaries midfielder Alex Tettey to receive treatment.
An angry on-field confrontation broke out after Fer's refusal to return the favour, forcing referee Mike Jones to step in.
He defused the situation by ordering the re-taking of the throw and immediately blowing for full-time, but Fer says he did nothing wrong and was merely acting in Norwich's best interests.
The Dutch midfielder said: "Would I do it again? If it was a 0-0 game, yeah, because I just want to win.
"I want to win every game and that's why I did it. When it hit the back of the net I thought I had scored the winning goal.
"Ricky said to me 'Just put it in the back of the net'. In Holland it's like that - if you get the throw-in you can play on. It wasn't a goal though and that made it more frustrating for us.
"I thought 'Yeah, the Cardiff players are going to be angry' and I just walked away.
"They asked why I didn't play the ball back to the keeper and I said I want to win the game. It was a difficult situation for the referee because the Cardiff players were angry."