After 24 hours struggle with this module, I feel I could update the docco at least for the benefit of those that come after me. What is the Perl way to get such things done, should I file a bug in CPAN, try to talk to the one author email listed in the module, or is there are way to mail the authors directly via CPAN?
Create a patch and upload that patch to the module's bug tracker. That way, others will be able to see your patch and apply it locally even if the author does not apply it. If you don't get a response within a few days, you could send an email to the author. There is one author listed in the POD for Statistics::Regression, but two are listed in RT.