yes, download it here (for 1.4.0):
http://panda3d.org/download/panda3d-1.4 ... -1.4.0.zip though its not most recent. the online manual is a wiki and that download link is just a snapshot that is generated once every release.
there isn't any packed manual for this release. I guess it's simply because Josh Yellon made some damage to the files, so I assume he'll wait until it's fixed or so, I don't know.