In my view, you can attack an MRP finding on these bases: classification, precedent or 'the vibe'.
Let's tackle the first two together. Careless is the right decision. While Duryea deliberately tried to hit Ballas, it's difficult to say that Duryea deliberately hit Ballas
in the chops (which is the part that leads to a suspension). He just swung behind him without looking, which is careless. The difference to the other elbows on the weekend was that all knew where the other players' heads were when they threw the elbow.
Dawson's suspension from last year is a good comparison. He dropped the elbow on Cameron pretty hard, but you can't say for sure he was going for Cameron's head. It was just careless - which is why the MRP also found Dawson's elbow to be careless.
The only contentious part is impact. The hit on Cameron was deemed to be 'high' impact, in part because Cameron had an enormous sook about it, and then ran around the field dressed liked a mummy. No doubt the GWS Doctor also dobbed on us. Ballas is made of tougher stuff, so neither he nor the club Doctor likely had as big a sook.
You could make a case that it should have been medium impact. None of us have seen the medical report, nor know how much it hurt, so we're all guessing. My guess: it's probably right on the line. I reckon Duryea was a bit lucky.
As for the vibe - that it doesn't seem enough of a penalty - I'm not sure that argument is very compelling for non-Freo fans. A non-Freo fan would have seen Ballas having a cheeky crack to a player exposed on the ground, that player reacting, and Ballas copping an errant elbow to the mush. A non-Freo fan would say that the vibe is that Ballas got more than he deserved, but that Duryea wouldn't have thrown the elbow back for no reason. I think it's fair to say there are few Freo fans on the MRP.
And hypen, I fear there may be people who actually want to strangle me so a photo probably isn't the best idea. But I like to be helpful, so here's an artist's impression.