Reading the blog about gimmes it clearly states that pros and above can only take a putt 2 and under and hacks and amateurs can only take a putt 4 feet and under. So WGT didn't give a pro a 6.6 foot putt.
However the OP could have, probably by mistake ,conceded a 6.6 foot putt. But his opponent would not concede his 2.1 foot putt.
Unless there is a bug with the gimmes that is the only way it could have happened.
If both players were pro and above the only option for gimmes is practice mode.