England batted for almost two full days to save the match at University Oval, with McCullum and his England counterpart Alastair Cook calling an early end to the final day's play with the visitors 421 for six, a lead of 128 runs.
Just 15 overs were left remaining in the day's play, and even if they dismissed England inside three overs there was little opportunity for New Zealand to blast an unlikely victory despite the small ground and benign pitch.
England had been placed under enormous pressure on Saturday when McCullum declared New Zealand's innings at 460 for nine, a lead of 293 runs, and the visitors knew they needed to bat more than five sessions to save the game.
Led by Cook and Nick Compton's 231-run opening stand and nightwatchman Steven Finn's stoic knock of 56 that almost lasted five hours, the visitors were able to ensure they thwarted New Zealand's attack for 170 overs.
Apart from the loss of more than 100 overs of play, virtually the entire final session on the third day was also washed out. McCullum, however, felt the pitch had also benefited the batting sides from the extra time under covers.
"I think it's hard to judge it because of that first day being washed out," McCullum said when asked if he felt the pitch had lacked any teeth as the match wore on.
"I think a couple of years ago (here) against Pakistan we saw a bit of variable bounce and a bit more reverse swing as the pitch got more abrasive as well.
"If there was a sixth day in this test match then maybe that would have unfolded.
"(But) I'm certainly not unhappy with the pitch, it was obviously hard work for the bowlers but it would have been nice to see what it would have done on another day."
Despite the lack of penetration for the bowlers, McCullum felt they had performed well and continued to run in with enthusiasm late into Sunday's play even though the pitch was offering them nothing in return.
"I thought the bowlers were huge today to stand up and bowl as well as they did and for as long as what they did on a pretty unresponsive pitch, which was obviously still only a day four pitch, it was a phenomenal effort," he said.
"I think they will be stiff and sore tonight but they will know they were standing up trying to bowl us to a win and you know that's exactly what you want from your bowling lineup.
"I'll look back on that test match and think it was an outstanding effort from our team and it is the standard we need to be operating at more consistently in test cricket."