fMRI is a tool. Just like every other tool it can be wielded skilfully or incompetently and in the case of fMRI you must do your stats properly (c.f. the Multiple Comparisons problem [1]). There's nothing out there that 'debunks' fMRI as a tool.
Edit: Indeed fMRI allows us to do things we had no hope of doing before, e.g. communication with those who are otherwise in permanent vegetative states [2,3] (that guy was my co-supervisor).
If Adrian Owen was your co-supervisor, you should know better than to say that fMRI allows you to communicate with patients in a vegetative state. VS means, by definition, that the patient is unresponsive. Communication via fMRI or brain computer interface is still only possible with patients that are conscious (e.g. locked in, or in a minimally conscious state).