Moltzen was playing beyond good before his injury at fullback its common sense to put him there now. The only reason he didn't perform is because of his knee, you lose alot of confidence when you suffer a season ending injury.
No he may not be up to the task of first grade fullback atm, but he has just returned back from a knee reconstruction and to get hes confidence back you need to play him at the position he has always played when there is an opportunity too. He hasn't played at the position for a while due to his injury so he is going to be rusty, you cant just get rid of him because he played horribly.
If Sheens got rid of marshall last year when he wasnt playing anywhere near his best like this forum suggested i doubt marshall would be in the form he was for the rest of the season, solely because he would of lost shit loads of confidence getting dropped.
Now i can rabble on all day but im not the fact is moltzen needs the confidence hopefully he learnt from his mistakes and will come back at FULLBACK next week if mckinnon is injured, and prove what he is capable of.