Erhard's infected son quest. Where's the son?

[Ponsau]

I've been up and down the island. I have now mapped every inch of eldfell and the island of fire. I still cannot find his son. I did shoot 1 infected across a lava stream thinking that was him. He wasn't in an area I could easily get to. He dropped a potion but that was it. Nothing saying that it could have been his son. When I go to Erhard, nothing happens and the quest is still active. I found some others who had the same problem while searching for a solution on the Internet. Is this a bug? Or is there a way to find him or have him respawn in a week?

[Ponsau]

Sorry, I finally answered my own question. The flesh eater I hit from a distance across the lava was Erhard's son and he did finally accept the death of his son.