Particularly bad are the visual comparisons. What the hell is he looking at? In most cases he is simply wrong and you can see it with your own eyes.
- the sketch of Zodiac has much thinner nose
- the feathered arrows do not match, the feathers are drawn distinctly differently
(Part 2)
- the ampersands don't look the same to me
- the crosshairs absolutely do not match.
It leaves me with the impressions that he has decided Doerr is the Zodiac and will take any bit of evidence and stretch it to fit that notion.
edit: the feathered arrows look more like evidence against the idea he's Zodiac. He drew arrows a different way.