FB,
Yes, dexamethasone is allowed if declared pre-tournament. AFAIK, LCW did not submit the declaration of use pre-tournament. If he did, this wouldn't be happening to him.
Does the level in the urine support his claim of medicinal use i.e. low levels? We don't know that information.
I think since it is allowed out-of-competition, it isn't tested for in out-of-competition random urine samples. This is definitely a loophole in the procedures by WADA. If it sets different standards for testing in and out of competition, the potential for errors by players and their support staff is increased.
The paper that SS has linked, as a scientific review, is very opinion based - the selection of articles was not systematic. i.e. what was the search strategy for research papers in electronic research database?
I do note that the doses of steroids (prednisolone) used that support ergogenic effects in human studies (that were quoted) were very high. Lower doses of steroids were not found to have ergogenic effects.
Although that author also quotes some animal studies, I place little emphasis on animal effects as time and time again, many animal studies do not extrapolate well to the human scenario (for the interested person, this field is called 'evidence based medicine').
Personally, I think nine-twelve months is sufficient if he had no intention. 24 months is for cheating. Some have argued that a person's right to hasten recovery is cheating. The International Olympic Committee are very clear that athletes have the right to health first and foremost. So, recovery back to your baseline is not a crime (after all, all us layman do that as well by taking medicines) and is not cheating.