Kinghorn had the chance to win the game with a kick he would expect to make, but skewed his effort wide of the posts having been superb in the game to that point.
He has spent most of his international career at fullback or on the wing but has been handed the number 10 jersey after the mercurial Finn Russell was axed by Townsend earlier this year following a reported falling out.
"Blair will feel it more than anybody," Townsend told reporters. "In the dressing room afterwards he was down, so I talked to him about the technical side of things as he can’t dwell on a kick that doesn’t go over in the last minute of the game, or anytime.
"I know it is easy to say but it is about what you learn from these situations. Is it keeping your head down longer? Is it the follow through? What technical things do you have to work on?
"Obviously it is going to hurt but that is sport – the width of a post decides whether you win or lose sometimes."
Townsend said he will continue to back Kinghorn less than a year out from the Rugby World Cup in France.
"He has to use this as a learning for him so the next time he gets the chance he knows what to do technically. He did a lot of things we wanted him to do well, and he led the team in attack and had done that all week in training as well."
Townsend was left to rue a lackluster first half from his side as they trailed 6-5 at the break, only to roar into a 15-6 lead early in the second period, though ultimately they could not hold on.
"I don’t think we fired that many shots in the first half and played a little bit inside of ourselves when we got in the opposition 22 in particular," Townsend said.
"But that changed in the second half when there was more movement of pass and shifting the target, which got more of our ball carriers into play and we created opportunities."
