Lee Bullen's weak header back lead to Owen Morrison's 90th-minute goal, a strike which incensed Wednesdayites due to the nature of his move to United two years ago.
Some of the home crowd shockingly booed and jeered Bullen after his mistake - obviously forgetting the role he has had in Wednesday's two-month unbeaten run.
But Sturrock did find positives from the game despite the lacklustre defending throughout the game and claimed the team played well once Steve MacLean had equalised Nicky Summerbee's early goal.
He said: "The first 20 minutes cost us. People can point to a basic error in the last minute but in the first 20 minutes we wasted the game.
"The second-half performance represented the best we've played for a long time without finding the net."