Coach Michael Bradley felt the sin-binning of Matt Scott was the turning point in Edinburgh's defeat by Glasgow.
Scott received a yellow card for a dangerous tackle on Rob Harley with 12 minutes left and the game tied at 9-9.
"It was a crucial decision," said Bradley. "The yellow card was decisive in terms of the balance of power.
"The referee was next to it and didn't seem to put his hand in his pocket or stop the play even, and the touch judge saw what he saw."
Referee Peter Allan took his cue from his assistant Andy Macpherson and, within moments of the visitors going down to 14 men, Moray Low crossed the line to score the only try of the game and put Glasgow in command.
"We had a lot of possession for all of the game," added Bradley.
"I thought we played particularly well. Even when down to 14 men, Jonesy (Lee Jones) was almost down in the corner.
"You don't automatically lose a game because you are down to 14 men, Glasgow lost a man last week and coped well.
"We just didn't take our chances, but we were excellent tonight. It was a fantastic performance.
"We created a lot of half-opportunities. Glasgow's defence has been very good and they were able to snuff them out, but they were under a lot of pressure."