In many areas, for years "poppers" were almost a first line drug. Not saying it's right, but that's the way it used to be. Now, as was noted, "proving" someone is faking is a waste of time and is basically irrelevant. If they are going through all the trouble of feigning unresponsiveness, let the hospital deal with the drama. Whatever the reason for their act, it's nothing we will be able to "fix" in the brief period they are with us. Psychological issues, domestic problems- nothing we will be able to cure in a few minutes. Besides, in my book- quiet, compliant, and passive is far better than angry and combative.
I found that over time, many people even developed a tolerance to these things- they simply had no effect on them.
Now some of the justifications I heard for using them are so that we do not "overtreat" someone who has no serious medical issues, but if we check a blood glucose, maybe push Narcan, then what else will we do for someone who has stable vitals? Yes, there is a cost factor, but really, we cannot be concerned about that either.
If a person has a simple syncopal episode- from fear, emotional distress, pain, etc, then they will quickly wake up on their own anyway. Treat the underlying problem and transport.