Some comments:
1) You skipped a few conditions where you test against True.
2) Avoid using Lists when you don't really need them. Use tuples instead they are less costly.
[commit.author.name, commit.author.email] not in [[auth.name, auth.email] for auth in self.authors]:
(commit.author.name, commit.author.email
) not in [
(auth.name, auth.email
) for auth in self.authors]:
3) Too much
if self.verbose:, considering refactoring, something like
vprint "[LOG] Initiating LogParser()"
4) Although not a big deal, but pythonistas tend to be anal about line width. (I think the convention is 70 or 80 characters), You could do something like this:
self.date = datetime.date(
int(self.commit_strings["Date"].split()[5]),
MONTHS_TUPLE.index(self.commit_strings["Date"].split()[2]) + 1,
int(self.commit_strings["Date"].split()[3]))