I can't take these claims very seriously. There is no proof that I can see. David Bawden's website is still up, in which he claims to be pope. Wouldn't he have to take that down if he "repented"? Maybe you could say he retracted his ways in his last moments, but then, where's the proof?
The obituary is a little strange inasmuch as it refers to him as "Father David", but that was something he obviously didn't write. I think it's a lot more likely that either the people who published the obituary didn't want him to be referred to as the pope, or more likely it was written by a family member who was embarrassed about his claim to the papacy but didn't want to refer to him simply as if he were a layman, so they chose "Father David" as some sort of middle ground.