Puzzling javadoc behavior

[rodrigobraz.removethis]

I am using javadoc and found some puzzling behavior. Can anyone please
explain it to me?

I have the following directories

mypackage
temp/mypackage

and files

temp/mypackage/SomeClass.java
mypackage/SomeOtherClass.java, which contains the illegal character
\35, on purpose. The reason for that will be soon clear.

javadoc -d docs temp/mypackage/SomeClass.java

Gives me the message

..\mypackage\SomeOtherClass.java:3: illegal character: \35

My question is: why does javadoc even look at directory mypackage at
all? It was told to process temp/mypackage/SomeClass.java only. In
other words, why are files in mypackage relevant at all?

In fact, if I rename mypackage to something else, everything works as
expected.

Clearly, javadoc is assuming there may be a source code tree with the
processed packages from the current directory, but was is the purpose
of such an assumption?

Any help appreciated. Thank you.

Rodrigo