b"h
here is what i read on your site :The Chasid heard the spirits of two deceased girls conversing. (Ein Yakov - we cannot understand this and the coming episodes simply, that Tzadikim sought to communicate with the dead. This is forbidden! Rather, it was all through dreams.)
however this is what the rambam writes (Hilchos Avodah Zarah 11:13):
Eizehu Doresh El ha'Meisim? Zeh ha'Mar'iv Es Atzmo v'Holech v'Lan b'Veis ha'Kevaros K'dei she'Yavo Meis b'Chalom v'Yodi'o Mah she'Sha'al Alav. v'Yesh Acherim she'Heim Lovshim Malbushim Yedu'im v'Omrim Devarim u'Maktirin Ketores Yeduah etc.
Clearly the dream element does not answer your issue.
The Rambam says that the prohibition of Doresh El ha'Meisim is only if one goes to a cemetery with the goal of communicating with the Meisim and takes steps in order to achieve that goal. The Chasid in the Gemara did not go there for that purpose and just chanced upon the conversation between the spirits.
Kollel Iyun Hadaf