In the 62nd minute Mr McDermid ruled that Adam Murray had pushed Lee Peacock as the Swindon sub went to meet a Ricky Shakes cross from the right wing. Christian Roberts drove home the spot-kick for his third goal in successive games.
But five minutes from time, when Robins skipper Ady Williams appeared to pull over Torquay sub Jordan Robertson, Mr. McDermid waved away the appeals of the home players and an angry crowd.
Even Sturrock, who has seen his new team beat Carlisle (3-1) in the FA Cup and now Torquay in the League in his first two games in charge, admitted that Torquay were unlucky to lose.
The Gulls have taken only two points from 27, and they haven't scored in the league for more than eleven hours. Non-League Leatherhead in the Cup (2-1) are the only team they've scored against during that run. They were the better side for long periods, especially before and after half-time when they had Swindon hanging on desperately.
Leading scorer Jamie Ward missed three good chances, Kevin Hill went close with a volley and a header and Lee Andrews hit the bar with a deflected 25-yard shot.
Both teams made changes at half-time, Torquay swapping Steven Reed for Stev Angus at left-back and Swindon sending on Peacock for Aussie striker Royce Brownlie.
Still Torquay piled on the pressure, with Ward failing to beat goalie Phil Smith one-on-one, Mickey Evans forcing Smith to a full-length save and Lee Thorpe having an effort cleared off the line by Williams.
Roberts' penalty knocked Torquay for a while, Nathan Abbey tipping a Peacock header over to keep his side in the match, but they staged a grandstand finish and nearly snatched a point with a Ward shot pushed round by Smith and then that penalty that never was.
Mr. McDermid also booked three players – Hill for Torquay in the first half and Peacock and substitute Michael Pook for Swindon in the second.