The Englishman started Sunday one shot in front of playing partner Scott and was just one shot behind the Australian when the duo strode to the par-five 12th tee with seven holes remaining in their round.
The longest hole on the Kingston Heath layout had not given Poulter too many problems during the week, but on Sunday the 36-year-old found three bunkers and had to hole a putt from off the green just to escape with a bogey.
It was his second shot from one of the many fairway bunkers on the course that raised the eyebrows of onlookers, as Poulter chose to attack with a hybrid club in an attempt to move the ball up closer to the green.
But he could only manage to move the ball on 20 metres and into another bunker, as Scott seized the initiative and never looked back in claiming his inaugural Masters title.
That was not the only mistake Poulter made on his back nine, with the world number 16 also culpable of shooting over the green from close range on the par-five 14th and then missing from two feet on the 17th.
But it was the curious club selection on the 12th that drew most of the questions from the media after his round and a confident Poulter remained defiant that he would use the same hybrid "100 times out of 100".
"It wasn't a mistake in club selection - it was a poor swing," Poulter added.
"If you are going to make a poor swing in that situation then you are going to get punished and I did.
"I made a good six in the end but a bogey there is costly and obviously a bogey on the next par five was also very costly."
Despite the problems late in his round, Poulter felt his week in Melbourne could still be classified as a successful one and he hopes to return next year and have another shot at winning a second gold jacket.
"It's been a good week," he said.
"I am disappointed obviously I haven't won as it would have liked to have gone out there and beaten Adam.
"But if you make a couple of mistakes like I made today [Sunday], certainly on those two par fives, then unfortunately you're not going to win."
Poulter has two more tournaments to play in 2012 - the World Tour Championship in Dubai and Tiger Woods' World Challenge in California - before he has a brief break from golf.
But Poulter will be back in action early next year and has already set his sights on adding to his 16 wins as a professional in 2013.
"It's not Ryder Cup year next year but I'm at the stage of my career where I've won some big tournaments and I have to focus on the bigger tournaments - the bigger tournaments being the majors," he said.
"But every tournament I approach now I have to be aggressive and believe that I can go out there and win every tournament I play and if I have that mindset and be stubborn about it, then I'm going to be tough to beat.
"As long as I can be in contention week in, week out, then I'm doing my job."
Scott's sense of relief was plain to see after his first tournament victory since August 2011, but arguably more importantly his first gold jacket at the Masters after a series of close calls last decade when he lacked experience.
The 32-year-old fell at the final hurdle in the 2002 and 2003 Masters - beaten in a play-off on both occasions by more seasoned opponents.
But this time around it was a different story as Scott showed his class and maturity to edge past Poulter.
"I'm really, really happy with what I was able to do this week and especially today [Sunday]," Scott said.
"It was the goal coming out here and probably it's the only week of the year where I've put four really solid rounds together and the result shows.
"The jacket I am going to have to grow into, but that's all right. Maybe it fits better when you win more of them. But it's pretty awesome to be able to slip the Australian Masters jacket on."