Acting umpires boss Luke Ball has admitted St Kilda were on the wrong end of two bad decisions during the closing stages of the Saints' narrow loss to Hawthorn, amid a perception umpires are cracking down on the 15-metre kick rule.

The mistakes many believe cost the Saints the four points in Launceston were acknowledged by Ball, who has taken on umpiring department duties following the departure of Wayne Campbell.

Ball referred to marks not paid due to the ball not carrying the 15 metres in distance in consecutive kicks from St Kilda players Leigh Montagna to Sean Dempster and then from Dempster to Shane Savage.

Ball told the Sunday Football Show: "Those two [decisions] looked like clear wrong calls."

Umpire Andrew Stephens believed the ball had not gone the legal distance. Hawthorn skipper Luke Hodge suggested umpires were policing the 15-metre rule more stringently across the round and called on the umpiring department to convey this to players.

"It did seem like through the whole round they had a [focus] on making sure if it wasn't 15m or 20m then call play on," Hodge said.

"I can understand if the umpires are focusing on it then let the players know. They might not go for that one, which is just on the 15m [borderline].

"They might go for a longer option. But a lot of players were surprised by it."

Dempster appeared shocked when he was told to play-on. Seconds later his kick to Savage, which looked to have carried the full 15 metres, was ruled too short for a mark to be paid.

Savage was then brought to the ground by Paul Puopolo, with Jordan Lewis grabbing the ball and kicking a goal for Hawthorn.

The Hawks won by three points.

Of the apparent crackdown, former champion Essendon forward Matthew Lloyd said: "There's no doubt it was the rule of the weekend."

Hawks coach Alastair Clarkson warned his team's luck was due to run out following two weeks of nail-biting victories over the Western Bulldogs and St Kilda.

"Probably two weeks in a row the better side has lost. St Kilda played a better brand of footy today than we did," Clarkson said.