FREMANTLE coach Ross Lyon didn't want to blame two crucial 50m penalties for his side's 17-point loss to Adelaide at Adelaide Oval on Sunday night.

The most contentious came in the third quarter when Dockers midfielder Bradley Hill threw grass at Crows forward Lachlan Murphy as he was walking in to take a set shot at goal.

Murphy missed his original shot but made no mistake from his second attempt from point-blank range.

CROWS PIP DOCKERS Full match coverage and stats

Then in the last quarter, Dockers defender Darcy Tucker was penalised for putting the ball on the ground, and not handing it to Crow Alex Keath, after he kicked out on the full.

Both decisions resulted in goals to the Crows, who held on to win 7.9 (51) to 5.4 (34) in a scrappy contest.

"You want to be playing well enough to take umpiring decisions out of it," Lyon said.

"The grass, (it) probably was (a 50m penalty) if you look at it, I haven't seen the replay of it.

"Was it around the edges and marginal, the grass, or was it a clump (of grass), I don't know, only the vision would tell us that, but probably to the strict letter of the law, you probably shouldn't throw grass.

"I haven't seen the footage, so I can't comment."

WATCH Bradley Hill penalised for throwing grass

Lyon thought the Tucker decision was more clear-cut.

"He dropped the ball in possession, you need to return it on the full," Lyon said.

"Some laws are black and white, it's costly in a tight game.

"Sometimes the rub of the green doesn't go your way, but you want to play well enough to take that out of it."

Pressed on if the Hill decision fell into the grey area, Lyon replied: "I've never really commented on umpires.

"Even after losing Grand Finals when the ball's hit the post for a point in '09 [when he was coaching St Kilda], so I'm not going to start talking about a home and away game.

"The game's got enough beauty in it and enough analysis without drilling in.

"Our umpires have an incredibly difficult game to umpire, I think they do a very good job.

"Players make more mistakes than umpires, so let's focus on the two teams because then you get more in-depth analysis and more interesting articles."

WATCH Ross Lyon's full post-match press conference

Lyon added he was proud of his players, but they needed to lick their wounds ahead of next Sunday's encounter with Richmond at Optus Stadium.

"We're a young team that is standing up and that is improving our footy, but we've got to keep it going," he said.

"Sometimes when equal force meets equal force, you need to be able to execute, and they (the Crows) were able to do it just a little bit better."