Anyone have any thoughts on this film being related to the original signing of just the letter "Z" from Zodiac?

http://en.wikipedia.org/wiki/Z_(film)

Z is a 1969 French language political thriller directed by Costa-Gavras, with a screenplay by Gavras and Jorge Semprún, based on the 1966 novel of the same name by Vassilis Vassilikos. The film presents a thinly fictionalized account of the events surrounding the assassination of democratic Greek politician Grigoris Lambrakis in 1963. With its satirical view of Greek politics, its dark sense of humor, and its downbeat ending, the film captures the outrage about the military dictatorship that ruled Greece at the time of its making.
Z stars Jean-Louis Trintignant as the investigating magistrate (an analogue of Christos Sartzetakis, who 22 years later was appointed President of Greece by democratically elected parliamentarians). International stars Yves Montand and Irene Papas also appear, but despite their star billing have very little screen time compared to the other principals. Jacques Perrin, who co-produced, plays a key role. The film’s title refers to a popular Greek protest slogan (Greek: Ζει, IPA: [ˈzi]) meaning "he (Lambrakis) lives".
The film had a total of 3,952,913 admissions in France and was the 4th highest grossing film of the year.[2] It was also the 12th highest grossing film of 1969 in the U.S. Z is also one of the few films to be nominated for both the Academy Award for Best Foreign Language Film and Best Picture.

I find it interesting that "Z" was used as a popular Greek protest slogan and means "He lives".

Could also be related back to the book they mention as having the same name. I do find the signing of "Z" and the timing of this movie that became the 12th highest grossing film in the US in 1969 to be very coincidental.

Here is a pic of, what I believe to be, the original book that was released in the US in 1966 as well….

http://www.baumanrarebooks.com/BookImages/67657f.jpg

Thoughts?