I after obtaining the full story, when their part remains were recovered in 2005, asked the Australian government to award him the DFC, which would have been fairly correct for his action.
Actually Herkman there is a very good reason why a DFC would not have been "fairly correct for this action". At the time the only awards which could be given posthumously were the Victoria Cross, the George Cross and a Mention in Despatches. There was thus never any chance of his being awarded a posthumous DFC, as such a thing didn't exist at the time. He could have been put forward for the VC of course, but there was never any chance of one being awarded 60 years after the event. This situation was rectified in the John Major reforms of 1993, but the rules were not made retrospective. Now all gallantry awards (but not orders) can be made posthumously.
I have been in the medal business for over 30 years and in my opinion retrospective awards are a real can of worms. Once you start going down that road, as Parabellum has already said,for every one you give out there will be a dozen hands shooting up saying "what about my dad/husband/uncle" or even "what about me". Best left I think, the system will never be perfect, but it's better than a lot of others I could think of.