For the second time in six days, Greene settled for fourth as Great Britain's 4x400m relay team left it just too late.
He joined forces with Conrad Williams, Jack Green and Martyn Rooney, who left his charge for the line on the anchor leg just fractions too late.
Red hot favourites USA settled for silver as Bahamas won a shock gold while Trinidad and Tobago completed the podium, finishing just a tenth of a second ahead of Great Britain, who posted a season's best 2:59.53.
"That is two fourth place finishes at my home Games - and they're right what they say about it being the worst place to finish," he said.
"I've had two days of feeling sorry for myself and it's gutting to just miss out again.
"What happened in the hurdles was pretty hard to take and I felt very down about it and the guys in the camp could see I was pretty low.
"They did a brilliant job raising my spirits and I was really looking forward to getting out there again."
Greene added that he didn't run in the heats because he was not mentally ready and while he ran the slowest split of the four athletes, he insisted improving his flat speed was key to become a better hurdler.
"I thought I did a fairly solid leg, it was what I expected really and I don’t think I lost us that much ground," he added.
"The team as a whole did a strong performance, posted a stronger time than in the heats but unfortunately it was not quite enough, which is disappointing.
"But I want to be part of this team, I have missed out on relays before because of the schedule so this year when asked I said definitely.
"It was amazing to be out in front of the crowd again but it's disappointing to be so close to a medal again.
"But the guys did an amazing job we couldn't have done anymore."
- Martyn Rooney