Tight Brain/Mind Linkage as Evidence against Dualism?

In a comment in the Maverick Philosopher's blog entry "Naturalistic Versus Theistic Ultimate Explanations", Kevin Kim had this to say about his view of the mind/brain relationship:

Regarding mind-- I lean toward a naturalistic explanation because I'm scientifically biased: show me a disembodied mind and I'll change my position. From what we've learned through science, mind (consciousness, or however we define "mind") is inextricably tied to physicality. When something affects the physical brain, it always observably affects the workings of that person's mind, as can be seen through alterations in a person's behavior: the case of Phineas Gage is a classic example of someone who suffers an extreme head injury and literally comes out of the experience a different person.

How does the tight linkage between brain and consciousness (which I'll abbreviate 'TL') mitigate against substance dualism (SD)? Because TL is not inconsistent with SD, it can't logically rule out SD. Does it function inductively to make SD less probable? I don't see how, but if you think it does, show me your argument. As far as I can tell, the most it can do is to leave open the possibility that some day there will be an explanation of consciousness in materialistic terms that will make SD superfluous.