All this means is Kenobi had two students and one of them murdered the other. At this point in time Vader wasn’t Luke Skywalker’s father. Lucas was making Star wars up as he went. The first retcon was Vader being the father. Which he hadn’t planned in advance anymore than Vader being a big deal, he wasn’t he was Tarkin’s henchmen in Star Wars. There was no grand Saga of Darth Vader 1-6. It is hilarious that there are still people who believe Lucas for instance that he always intended Leia to be Luke’s sister.

Lucas doesn’t give a damn about canon. He was always loose and free with it with Star Wars, and even more so with Indiana Jones.