Everyone was wearing NWUs under their FFEs.
The test quoted says that it took a direct flame to each service's fabric for 12 seconds, which melted the NWU and charred the other two.
So I suppose if someone were to stand in the fire without FFEs, the NWUs might have melted, but then you have to ask yourself why someone would do such a silly thing. I doubt that standing 4-6' away and putting a fire extinguisher on a small fire that just started is going to cause the NWU to melt to anyone's skin, and if that fails you send personnel in FFEs to fight the fire.
There is the whole battle-damage possibility, but it's likewise hard to imagine someone who survives a hit to the ship but instantaneously finds himself in the middle of a blaze that melts his uniform to his skin. I'd like to hear the voices of experience to know if that's how it actually happened.
I hate the NWU as much as the next guy. I'm just pointing out that the only real-life scenario that occured doesn't support the study.