AFL UMPIRES boss Jeff Gieschen has conceded the free kick against Adelaide midfielder Scott Thompson against Hawthorn was an 'error'.
 
Thompson was penalised for pushing Hawks ruckman David Hale in a marking contest, costing the Crows a set shot at goal during the frenetic last quarter on Saturday.
 
The decision saw the momentum shift, and the Hawks ran away 11-point victors.
 
Speaking exclusively to AFL.com.au,Gieschen admitted it was the wrong call.
 
"We deemed it to be an error by the umpire," Gieschen said on Monday.
 
"The questions you have to ask are - was it a hand in the back? No … it was a bit of a touch in the shoulder.
 
"Was it a push-out? No, it wasn't a push-out either. For it to be a push-out, there needs to be a degree of force, and there needs to be a straightening of the arm, and we can see a visible push-out. But in this case, no it wasn't hands in the back, and it wasn't a push-out in the marking contest.
 
"(There was) a little bit of incidental contact on the shoulder, but certainly not a push-out.
 
"So it was a mistake by the umpire and our coaches have spoken to Ray (Chamberlain) about that and he was comfortable with it as well. Just a mistake in this situation."
 
Last week, Brisbane Lions midfielder Tom Rockliff labeled the pushing rule 'bizarre', claiming he was unaware he could not push any player in a marking contest.
 
Rockliff's remarks have surprised Gieschen, who says it is outlined on the Rules of the Game DVD.
 
"I've been to Brisbane personally myself, not in the last couple of years, but I think Hayden Kennedy went there in the last couple of years but every year we show the DVD and it's very clear on the DVD," Gieschen said.
 
"So it gets talked about quite clearly on the DVD and when we're instructing the clubs it says you cannot push, bump or block, hold or interfere with the arms in marking contests.
 
"It's been around for 10 years on DVDs where we've explained it to clubs so that surprises me a little bit. It may be time that some of the clubs went back and revisited the DVD and showed it to their players just as a reinforcement."
 
Jacqui Reed is a reporter for AFL Media. Follow her on Twitter @JacquiReedAFL