I think that could perhaps have been your uncle's conscience. When someone we love dies, we think about all the things we should have done for them. It stands to reason that your uncle had these very normal feelings and dreamt about the only thing he could do for his father at this point. When he did it, his guilt issues were alleviated, thus no more dreams.
Now, that being said, I did have a dream about a dead loved one. My grandfather. I was staying with my grandmother and sleeping in the room at the front of the house. The outside stairs went over the closet in my room. So, I'm sleeping and was woken up by the sound of footsteps on the stairs. I got out of bed, went out the front door and up the stairs to see what it was. I wasn't scared at all. The upstairs was another dwelling. The one he died in. My gran had moved downstairs with her mother after grandad died. So, I walk in (the door usually stays locked), go through the living room, into the first bedroom (my grandad and grandma's room), then to the right to the next bedroom. I saw my grandad sitting up in the bed with the covers to his waist. He patted the bed for me to sit. So, I had a conversation with him. The gist of it was, he was telling me he was dead (I never went to the funeral--too young), wanted me to know he was feeling better now (he died of lung cancer), and that he loved me. We talked about other things, but I can't remember what. When we were done, he told me to go back downstairs and go to bed.
The next day, my cousin and I went upstairs to play. The door was locked as it should be. When I went to the back of the house, I noticed the bed was mussed. Just like it would've been had my grandad really been there. I later found out that he died in that room-not his bedroom. My grandmother had moved him in there because it was closer to the bathroom. I don't know if it was a dream, but it was very comforting. There are loads of stories I could tell about this house. Lots of people don't feel comfortable there, but I feel completely at peace when I visit.