If you watch the replay, you might see the following:
Kersten gets the ball 10 seconds after a centre bounce when every Freo player was behind the ball. There's no way he could even make the argument he was kicking to a Freo player as they knew they were all behind him.
If he was trying to kick a 70m goal, he didn't wind up like it. To me it looks like a chip shot to the pocket.
Had his kick gone straight it would have missed the goals by even more. As it was, the ball actually curved towards the goals, and still missed by 10m.
So, I reckon the call was available to the umpire. Again, I'm not sure it's the right one, but not out of the question either.
Having a rule based on intention is rubbish, but consider the 'bright line' alternatives. On the one hand, you get rid of deliberate out of bounds, and watch teams kick for touch or handball over the line whenever they are threatened. You reckon 'Rolyball' was dire, imagine if teams could just work their way up the sideline for stoppage after stoppage of 30 players. Rugby anyone?
The other extreme is the last touch rule. I actually don't mind that idea, but it would be a nightmare to interpret and then you'd have teams actually shepherding the ball out.
So, the AFL has gone with something in the middle, and tried to get the balance right. It creates problems, but perhaps it is better than the alternatives.
www.fremantlefc.com.au/video/2017-04-15/...tes-rd-4-v-melbourne