Is there a linguistic term for what is going on here? I read this phrase in a newspaper and it struck me as ungrammatical but at the same time I can see the logic.
It seems from the comments that my original question was not as clear as it might have been, so I will try to expand on it.
If you do something by dubious ethical means, that for me would mean you do it by means which are ethical but also dubious - this is obviously not the intended meaning, hence my double-take.
I think that on my initial reading, "dubious" is modifying "ethical means".
The writer, though, sees to be using "dubious" to modify "ethical", with that compound then modifying "means".
The original sentence is a bit more complicated than that, because "by legal means" can mean "using the apparatus of the legal system" (e.g. war crimes prosecutions) as well as "lawful". I think that's partly why the sentence originally struck me as strange, but perhaps it can be left on one side.
My question then is whether there is a specific linguistic term for the change in the function of "dubious" (or maybe it's "ethical", or maybe it's the syntactic structure) that occurs between:
(1) "dubious ethical means" = "ethical means that are dubious" / "means that are ethical and dubious"
(2) "dubious ethical means" = "means that are dubious from an ethical point of view".