The reason I bring this up is because of how he thinks through everything and anything that could have caused the problem. He then evaluates the person and really gets inside the mind and situation. He is an investigator investigating the mind of the subject. I think we as writers at times need to be investigators of our characters and their stories.
I was also the other day helping my son plan a campaign for a game. He was talking about the situation that brought the adventures to the certain local and explained that bandits were harassing the land. The interesting part was he did not want the bandits in a particular tower that he wanted the adventures to clear out he instead wanted it full of "vermin." I asked him why the bandits had not already cleared it out. We investigated this further and decided that the bandits would have already done so and so they had to be nixed from the adventure.
In writing about our characters we need to evaluate why they do what they do and if it doesn't make sense it is time ti nix it. We need to analyze and experiment with them. Test them here and there to see what they would do.
How do you test your characters?