I am curious to see it written here as Australian Painted-snipe rather than Painted Snipe. HANZAB says Australian is not necessary, although I understand that since then, there is thought to separate it from other members of the "species" outside Australia as another species. Maybe another allopatric example of where it is hard to define a species. I also understand that they are separate from the other group of birds also called Snipe. I don't know which group was named first as Snipe and so which "deserves" to be called "true" snipe. HANZAB says that the Painted Snipe was named by Linnaeus in 1758 so it certainly was early. If the other group was named later isn't the Painted Snipe then the true Snipe.
Either way calling it Australian Painted-snipe would require it to be indexed in books under P, rather than S and I don't see that this is being followed.
I had not noticed that they were bobbing, I noticed that most walking whilst feeding was very slow, although beak movements was quick. When they flew they are very unlike the Latham's Snipe: light and airy with fairly slow flaps and silent.
I think I agree that the smaller duller one does not look like an adult male.
Philip