New Zealander Hubbard, 40, led with a 120kg lift after the snatch discipline but had to withdraw with an elbow injury before the clean and jerk.
"I saw the photo of her and it was very clear she enjoys a physical advantage which is not possible for born women to enjoy, " McGregor told the Daily Telegraph.
"I was out back with her and my gut was to not go for the heavier weight, but she looked me in the eye and said, 'No no no, I want the 132, ' and I wasn't going to say no to her".
"But in the past Laurel Hubbard used to be a male champion weightlifter".
Described as an "introverted character" by New Zealand's weightlifting high-performance director Simon Kent, Hubbard admitted she had anxious about the crowd's reaction prior to competition.
Today she said she had seen medical staff and her arm was "busted".
"I hope all New Zealanders. would get behind one of their athletes that has gone through the pathway to achieve greatness, and within the rules of the sport".
However, the International Olympic Committee (IOC) states that for transgender women to compete, they must demonstrate their testosterone levels are below 10 nmol/L for "at least 12 months prior to her first competition".
Camera IconLauren Hubbard nurses her injury.
"It seems likely that I have ruptured a ligament, some insignificant tissue damage".
"I have no regrets about the attempts that I made, because I believe that to be true to sport you really have to try to be the best that you can".
In Hubbard's absence, Stowers won the gold with a total of 253, followed by Charisma Amoe-Tarrant of Nauru (243) and Emily Campbell of England (242). "But there's no indication at all that they were anything other than absolutely fantastic".
Hubbard allegedly made her changeover to be girl at the time of 35 and now she has fulfilled each criteria below Commonwealth Games policies to qualify for its ladies's over-90kg lifting celebration.
Touted as "a triumph for human rights and open opportunity", the decision to allow Hubbard to compete as a female tested the limits of political correctness as other competitors cried foul.
"This is something that members have expressed various opinions on and it's something that the weightlifting community needs to come together and have some robust debate, discussion, on", he said.