The linesman kept his flag down when Robinson latched on to Ritchie Wellens' through ball but raised it moments later when the striker's shot hit the back of the net. Leeds then went on to win 3-0.
Dickov said: "I haven't had an opportunity to speak to the referee yet but intend seeking him out for an explanation.
"I've had the benefit of replaying the incident about 20 times on the video and Theo is clearly a yard on side.
"But the late flag has baffled me as much as anything else. It looked as if the linesman thought he was on side but changed his mind when Theo scored.
"It's a massive decision because we were all over them at that stage and had we got a goal it could have changed the course of the game.
"We've gone on to concede a couple of poor goals from our point of view but I can't be too hard on the players because we had by far the better of it against a very good team.
"The first half was scrappy and you have to give them credit for taking their chances when they came.
"You can't afford to give players of that quality the opportunities we did but other than that I was quite pleased with the performance despite the result."