The Stine Letter

As I mentioned in a different thread I'm visiting San Francisco for a family wedding. It's my first time being on the west coast and being that its SF it sparked my interest in Zodiac again. I'm a huge crime buff and in fiom school always did shorts inspired by true crime and Zodiac was one of them. My trip to SF is short as I have only 2 1/2 days to myself and the rest is dedicated to the wedding, however, my hotel is 10 minutes away from the Stine murder scene so I get to finally walk that street,

Anyways..

One interesting topic that I haven't read in awhile was the Stine letter. I haven't seen the movie in awhile so I can't remember if it was discussed. The letter said he killed the driver on Washington Street and Maple Street. It was said that Stine wrote in his log he picked up Zodiax on Mason and Geary and supposed to be at Maple but ended up going a block down to Cherry.

So did Zodiac just forget the name of Cherry and put down Maple or was the Stine letter written in advance? With Zodiac the whole time and stamped and was ready for Zodiac to just put in a piece of his shirt?

Obviously nobody will know the exact answer it's all theories.