Double check again - check off the list below:
Corpse: Observe the corpse completely or else you will not move forward.
Front side: click on forehead-eyes, mouth, chest. Click on pustules to turn to the side view of face.
Close up of face: click on temple, eyes, mouth, pustules. Click on circular stone on ground left of the head and chin. Eymerich makes comment about different kind of plague.
Click on circular stone again - it is an ear. Automatically pull back from corpse.