The 3-2 setback at Tynecastle saw the Highlanders strike on each occasion with headers from set-piece deliveries flighted into the Edinburgh side's goalmouth.
Twice Gary Warren was afforded time and space to nod home, while Billy McKay pounced for his 18th league goal of the season to send him top of the Clydesdale Bank Premier League scoring charts.
McGlynn acknowledged his side's culpability in those goals but also pointed to the absences of out-of-contract captain Zaliukas, who looks like he has played his last game for the club after rupturing ankle ligaments, and departed defender Ryan McGowan as contributing factors.
He said: "The goals we lost were criminal defending. It was three set-pieces. That's where you miss guys like Zaliukas, who would have defended these set-pieces. You can't keep replacing guys like him and McGowan, who would have been big players at these situations.
"Was it a lack of concentration? It might come down to that. We had a man-to-man marking situation and there is a man nominated to mark the lad who scores the goals.
"It's quite simple. You pick up your man, you go with him and you attack the ball. But that's not what happened. It was run-of-the-mill, very simple stuff."
Visiting manager Terry Butcher felt the fact his side twice responded to Jason Holt and Andy Webster's goals from the home side to regain their lead proved their camaraderie has not been affected by their recent dry spell.
Butcher said: "It was a real battle and a real scrap. Heads could have gone down when we took the lead twice and were pegged back twice.
"There was a lot of character shown by the boys. We have gone back to second in the table, which is lovely. We are having a real slump but we're second in the table. It's wonderful."