I think you are operating on a faulty assumption: The desired outcome.
If they wanted the guys home, then maybe the UN would be the go.
If they were simply determined to posture and prance and fly the flag and dog whistle like mad while the gears moved towards the inevitable then try and reap a political reward, then they would behave much as they just did.
The rest is all theatre. All the cajoling. All the finger wagging. All the finger pointing. Theatre. I expect both governments got to hide some real dirt between the smokescreen of Chan/Sukamaran. As they do.
Had nothing to do with what was right or correct or fair.