Cook's decision not to enforce a New Zealand side low on runs and confidence to follow on in the second and final test, as well as the timing of England's declaration after they batted again, baffled some leading commentators.
Among those perplexed were former England players Geoffrey Boycott and Ian Botham, who deemed it a negative move. But Cook said a 247-run victory on Tuesday, which completed a 2-0 series triumph, was full vindication.
"The result definitely vindicates the decision, no doubt about that at all. To win by 250 runs is a good win, and in just over three days cricket effectively," Cook told a news conference after England made the most of a letup in the drizzle to take the four wickets they required on the final day.
"Tactically, we thought the wicket was going to get worse, that was the reason we did not enforce the follow-on.
"It's very easy when you are sitting behind the rope...when you're not making that decision and you're not responsible for it. You are judged as a captain on results and this game we have won by 250 runs."
Victories by sides following on has happened just three times in tests, including England's stirring win over Australia at Headingley in 1981 when Ian Botham, with the bat, and then Bob Willis with the ball, propelled an England side seemingly down and out to a remarkable success.
Cook said he did not want to take any chances against a side, who until they collapsed spectacularly to lose by 170 runs at Lord's in the first test, had matched England over the best part of four tests, including the 0-0 drawn series in New Zealand.
Batting New Zealand out of the game, he said, was priority number one with England setting the tourists 468 to win.
The world record second innings run chase stands at 418, by West Indies in 2003, - yet New Zealand had totalled 449 in three completed innings in this series before the target was set.
"We were 1-0 up in the series. We didn't want to give them a sniff because series wins don't come easily or very often," Cook said.
"We wanted to dictate those terms and make it as tough for them as possible."
Cook is still finding his feet as England captain after replacing Andrew Strauss last year, gave one example of how setting more defensive fields in this series had paid dividends.
"New Zealand have quite aggressive players and we have found in these games that setting slightly more defensive fields and stopping them scoring has been a successful way of getting them out," he said.