England defender John Terry made a goal-line clearance from Marko Devic's shot in a close and decisive group match in Donetsk on Tuesday, but replays showed the ball had crossed the line.
Ukraine needed nothing less but a win to qualify for the quarter-finals but Wayne Rooney's goal early in the second half ruined their dreams while the refereeing error has put UEFA under pressure to use goal-technology.
"We made a mistake, I wish we hadn't made the mistake but we did. Referees are human beings and human beings make mistakes," Collina said as quoted by AP.
However, Collina said Hungarian referee Viktor Kassai and his team of assistant refs would play no further part in the tournament, but the referee was not blamed. He further said Kassia would have found himself under too much pressure if he had stayed.
"Kassai is one of the best referees in Europe," Collina said.
Collina and UEFA executives faced grueling questions regarding Tuesday's decision and use of goal-line technology, which has already been test by FIFA in a friendly match between England and Belgium at Wembley.
UEFA said that out of 302 tight decisions made by referees in the 24 matches so far, 289 of them were correct and 13 wrong with 95.7 accuracy rate. UEFA's experiment with additional assistant referees had contributed to 16 decisions out of which 15 of them were correct.
"That's a huge result, even though we must still improve," Collina said.
"One was wrong," Collina said. "It was a human mistake made by a human being. Of course, it would be better if this was not the case."