Although Esdras knew that his rise in power was bound to attract suspicions he thought it was over already. And yet it looks like the issue was not easy to brush off to the point that an important figure got involved.
Evidently Esdras was not concerned that they would find anything against him, his possession of this body wouldn't get exposed with the investigation methods of this low level world.
Furthermore, Esdras already completed his assimilation to this body and the spirit of the original host thanks to the divine shard. It would be truly extraordinary if they found out the truth.
Esdras had nothing to worry about in this regard but nonetheless he was still vexed that some dogs were sniffing at his past.