He claimed that it was PD based on the lack of a copyright header, Alex Hudson noted that just because it lacks a copyright header doesn't mean that it is PD.
No, he did not. He claimed that "it has no copyright". That can mean a number of things(including that the author renounced his copyright in some way) and you are over-assuming.
I didn't over-assume anything. One can read the OP's sentence in several ways, one way is reading the content of the parens as "since it has no copyright header". The OP didn't state how he knows that the code is in PD; nor has he actually stated how he knows this. So _everyone_ in this thread are assuming things, including you.