The incident occurred on Lap 5 of the final race in the BetEasy Darwin Triple Crown when Whincup and Coulthard came to the pit lane both from within the top 10.
As Coulthard approached his pit box, Whincup, whose pit box was stationed immediately behind Coulthard, left his pit.
Coulthard said the incident could have had harsher consequences if he hadn't slowed down in time.
“I was trying to drive into my pit bay and I had to lock up for however much to not hit him properly,” said Coulthard.
“I obviously hit him, there was contact, but I'm trying to drive into my pit bay and there's a Red Bull car driving out.
“How much contact is too much contact? First of all. You've got team members, you've got lives, and things like that.
“I could have gone and drilled him much harder, but then it becomes a safety issue, which I obviously had the presence of mind that I want to have straight wheels on my car because I've still got the rest of the race to go.
“The question comes back to how much contact is too much contact.”
The incident ultimately cost Coulthard a chance to win the Darwin Triple Crown Trophy, which went the way of Whincup who finished equal on points with Coulthard.
Whincup was awarded Triple Crown title on countback having won the final race of the weekend.
During the post-race press conference, Whincup was posed with Coulthard's question; how much contact is too much contact?
“I suppose if the car barrel-rolled over the pit lane and up into the crowd – which wasn't there – that's probably too much,” said Whincup.
“I don't think it was a ‘thing', no idea what was going on strategy-wise,” he added when asked if Coulthard had purposely tried to block the seven-time champion.
“We were racing #17 pretty hard and the race was going to come down to the pit stops. We made sure we weren't going to get baulked by #12.
“We knew it was going to be close but we certainly weren't going to hand them the win on a plate.
“We were going to attack as hard as we can and that's exactly what we did. We got the reward for it.”
Mate if you didn't stomp on the middle pedal someone in either pit crew could have been injured. You did the right thing.