As a Pagan, I have no problem admitting I might indeed be a complete idiot for lighting candles and chanting in order to produce a result. Maybe that's delusional, but it's certainly not a threat. She gave no explanation as to how she had proved that magick didn't work, and she violated many sacred trusts in the process. I have a feeling the witches she worked with were on to her from the get go. In any case, her work was a piece of junk because it was wholly ethnocentric.
Common sense dictates lots of good things about self-preservation.
Beyond that basic instinct, common sense needs a little more education. But at the same time, rant aside, Pagans as a group need to consider in fairness we might be wrong. Perhaps the thickness to the atmosphere after an invocation simply comes from our own perception. Perhaps some of the things many of us have seen, and heard, and touched came from altered perception. Since I came to the religion as a deist skeptic and have experienced sufficient proof to believe, I rest on the spectrum that favors my being NOT delusional.