When the Prefect Lord contacted these two revered Lords to search the Extinction Domain, he was still guarding outside the Stone Tower. In other words, at that time, the Prefectural Governor had not confirmed with General Eddy that "Owen Bertram had been beheaded." From the Prefect to the two revered Lords, their knowledge only included "General Eddy took action against Owen Bertram in the Extinction Domain" and "General Eddy returned to Divine Village."
What Owen learned from the souls of the two Lords did not include an imposter General Eddy confirming to the Prefect Lord that he had killed Owen Bertram.
Therefore, Owen could not determine that this General Eddy was an imposter.
This led Owen to make a choice after considering it: he would charge towards Moon City Divine Village!