I've explained how I approach such paranormal phenomena in previous threads, like the one here. I think some non-Christian researchers have a tendency to underestimate the possibility of demonic activity, even though the demonic explanation can make so much sense of cases in which there seems to be a combination of genuine paranormal phenomena and deception or error. But however we explain the Piper case, it does seem that there was something going on that goes beyond the typical naturalistic worldview.
Here are some of Taylor's comments:
One of the more curious aspects of Mrs. Piper’s trance mediumship was that for a time (during the transition from communication via the voice, to communication via writing), three different ‘communicators’ could hold ‘conversations’ with three different sitters at the same time – one through voice, one writing with the right hand, and one writing with the left hand. Yet Gardner casually explains away this bizarre simultaneous three-way mediumship simply by saying Mrs. Piper was “strongly ambidextrous”. And there are other aspects that should give the curious mind pause before dismissing her as a fraud. Given her reputation after the first couple of years of investigation, Mrs. Piper could have left the service of the SPR and charged exorbitant amounts of money offering sittings for the rich and powerful, with much less chance of being caught. Instead, she remained on a compensatory wage under the skeptical eyes of investigators for a good portion of her lifetime. Further to that, if she was a fraudulent medium, why change ‘technique’ from voice mediumship when it was so successful, to developing simultaneous voice and writing (and at times communicating via mirror writing) for no additional reward or benefit? And how did she fool scientists and physicians that her trance was genuine, showing no reaction to pain sensitivity tests including surprise needle jabs, flames held to her skin, and long inhalations of ammonia?
Martin Gardner could have engaged readers with any of these topics, but instead he steers them away from intelligent discussion of this case. He ignores the source material completely, raising criticisms that were comprehensively dealt with a century before he wrote his essay, and impugns the integrity of the original investigators despite having no grounds to do so. If Gardner is, in the words of Stephen Jay Gould, “the single brightest beacon defending rationality and good science against…mysticism”, one would have to think that rationality and good science are in serious trouble on the evidence offered in this particular essay....
Unscientific skepticism of the type exhibited by Gardner and Cattel is a corrosive one which, rather than defending science, instead shields it from possible new discoveries and viewpoints through irrational over-protectiveness. It also brings skepticism as a whole into disrepute when such cheap tactics are employed. In his article “How Mrs. Piper Bamboozled William James”, Martin Gardner ignores the original scientific work done, misrepresents the competency of the investigators, and misleads the reader both through incorrect statements and loaded language. This is hardly the type of writing we would expect from “one of the great intellects produced in this country in this century.”