Nico considers this. Now that the man’s closer, he can see that he’s the right build and, yes, admittedly he does sound like Jason. Nico probably should have realized sooner, but he’s a little caught up in controlling the dead -

“I said no!” Another ghost is knocked away from the grave, its misty energy sucked down into one of the cracks in the floor. “I only want to talk to little one. And stop distracting me, Jason.”