A possible explanation for both those lines: Obvoiusly at some point Obi Wan moves to live on Tatooine to watch over Luke, who resides with Owen and Beru. Now, is it possible that, at first, Obi Wan and Owen get together every now and then and discuss the "old days", and as time goes on their discussions devolve into bitter arguements; Owen blames Anakins "death"on Obiwan, comes to think of him as reckless, comes to think that he lured Anakin away with exotic tales of the larger universe etc. And eventually it gets so bad they just stop talking to each other. This would explain those two lines ( that they are not based on what actually happened, but just on Owens beliefs and his opinion of Obi Wan), and also explain why Owen doesn't want Luke associating with him.