Erickson stressed a non-power pro-cooperation in his therapy. He repeatedly urged that we put one foot in the client's world, speak the client's language, empower them to use their resources, and help them associate their experience for their growth. In the intensity of hypnotherapy, that cooperative merging tends to blur the dualism of "I and Thou" into just a "here and now" - a network of mental association that happens to be greater than it was for a lone individual. Who situmlates whom to suggest what, is an impossible question to answer then.
But, then, anyone can analyze anything into little discrete parts - look at those parts as he-has-power / he-has-none, etc. After all, the universe is more likely a pile of vibrations than a set of solid object with a few forces here and there - but that has not stoped Plato, or Bohr, or Aquinas, etc., from making it into a dualism at every turn. It didn't change the Universe into a dualistic Universe...it just limited the theorist into the binds of dualism. So too, the reality of Erickson's work can be see through different theoretical glasses - but it doesn't make the work what the theory says it was. Case in point: the Haley analysis (1963) relied on the concept of "power" in the relationship (that being Haley's term, not Erickson's). So, is the power real because Haley say so? No, and Haley probably wouldn't take it to be real either...just a construct to attempt to explain and descibe at the time. It's hard to convey how incredibly client centered Erickson's time with patient's was (at least in the later part of his career when most of use studied him). One could summarize, Bateson as saying that Erickson's work was the best living example of that was contrary to dualistic science he had found.
I hope that shed some light on the subject.