AFL umpires coach Jayden Kennedy believes the controversial call to award a 50m penalty against Adelaide forward Eddie Betts in the dying stages of their loss over Sydney on Friday night was the wrong decision.

With six minutes to go in the final term and with the Crows up by nine, Callum Mills marked the ball on the defensive 50 and seemed to play on, although the umpire didn't agree.

He awarded a 50m penalty against Betts for tackling Mills, who subsequently passed the ball to Sam Reid inside 50 who kicked the goal and kept the Swans in the match.

When speaking to AFL.com.au on Monday about the incident, Kennedy conceded the call wasn't the right one.

"What we would have liked in that situation would be the umpire quickly call play on," Kennedy said.

"What we saw was Mills control the ball, and in our belief, he then made an effort to play on.

"The expectation is from us is when Callum did go forward on the mark and go through the play-on motion, our expectation as a group is to call play on."

"That would have been the best result for us."

Kennedy also touched on Lance Franklin's goal of the year contender, and suggested that while it may look like he took more than 15 steps, it would have been a tough call to make on the spot.

"I'm sure if the umpire felt he ran over the 15m, he would have paid it," Kennedy said.

"We paid two on the night, which I haven't seen for a long period of time, but it was a very marginal call as to whether or not he ran over the 15.

"I think if you go slo-mo, I think he's probably closer to the 20 than 15. That's a fact, but live, I think it would be really hard for the umpire to tell if he's run over the 15.

"It still could be [goal of the year], because we didn't pay a free kick."