Collingwood coach Nathan Buckley says he feels for the umpires who have to officiate the contact below the knees rule, after yet more confusion on Saturday night.

But Geelong superstar Patrick Dangerfield was far less diplomatic, labelling the decision to award a contentious free kick to West Coast's Jamie Cripps as an "absolute disgrace". 

Collingwood midfielder Tom Phillips was penalised when he slid into a contest involving West Coast forward Cripps.

There was confusion in the immediate aftermath, with Phillips' teammate Jaidyn Stephenson handing the ball back to the Magpie and giving away a 50m penalty.

Cripps converted from the resulting free kick, leading to Dangerfield's outburst on Twitter.

"Contact below the knees.. absolute disgrace," the AFL Players' Association president tweeted before following up with another swipe at the rule.

"Don't put your head over the ball kids. Lower and harder... na (sic) not anymore."

Speaking after the game, Buckley bemoaned the controversial decision.

"You could tell the level of confusion by the fact Stephenson thought it was Phillips' free kick and threw the ball back to him," Buckley said.

"Then we got penalised 50m for it. That was unfortunate for us. There's a bit of grey area in it and I feel for the umpires, because it's a hard one to officiate."

Jamie Cripps is knocked over by Tom Phillips. Picture: Michael Dodge, Getty Images/AFL Photos

Buckley said players can exploit contact below the knees by allowing opponents to slide into them, but said they risk giving away free kicks regardless of which way they try to bend the rules.

"Smart players exploit the rules all the time," Buckley said.

"It is exploitable, I presume. But every time you try to exploit it for head-high contact, you can be giving a free kick away or getting it. Every time you try to exploit it for contact below the knees, you can be in danger of giving a free kick away.

"It's really marginal."

Having led by 11 points at quarter-time, Buckley said Collingwood was "out-grunted" by West Coast in the final three terms and said it was a consistent theme against the Eagles.

That comes after three straight defeats to West Coast at the MCG.

"It's been pretty consistent … the way they have beaten us," Buckley said.

"We get off to a good start, they grind their way back in and then grind us out.

"I think there's a lot of upside for the way we went about tonight. There's a lot of improvement in our performance. We weren't at our best, but the opposition generally have a fair bit to say about that and they've bested us a few times.

"It's clearly something we'll have to look at when we next play West Coast."