Initialization of instance fields vs. local variables

Question

I have always been wondering about why in the following example it is OK to not initialize the instance field (relying that it will have its default value)

Answer 1

It's really just a matter of what the warning is able to tell you. There's really no way for the warning to be sure that some other method hasn't initialized the class variable, so it only warns on the one it can be certain isn't initialized.

Also, it's a warning and not an error because there's nothing technically wrong with using the unassigned variable (it's guaranteed to be 'false') but it's probably a logic error to have it unassigned.