Does it say if the researchers knew his family members' names in advance? Wouldn't the "a ha!" moment be when the patient shares something that the researchers couldn't possibly find out on their own and that wouldn't be interpreted via his family's help? None of that appeared to happen here.
Having said that, I've just skimmed the Nature article. But what stands out is that they had 86 days of unsuccessful communication before they changed strategies and then all of a sudden started reporting success. I really hope this works but we should remain skeptical for the possibility of abuse here. Other commenters in this thread have reported that the researchers have committed misconduct in their brain research.
The only thing I fear more than being in the discussed patient's situation is being in their situation and having my thoughts incorrectly interpreted at best or outright manipulated at worst.