When Library Juice Press or Litwin Books signs a contract with an author, the contract is typical for the publishing industry in most ways. One of the commonalities in publishing agreements is that the publisher doesn’t end up owning the copyright to the work, but they do get a temporary exclusive license to publish it. As a result, the copyright statement in the actual book can be misleading to readers who might want to republish or reuse part of the book. Our copyright statements make it clear that the author is the owner of the copyright, but it would be an error to infer from that that the author is the one who has the right to give permission to use the work. They may or may not be; that right is contingent on whatever the agreement is between the author and the publisher. That agreement is likely to be too complex to fully state on the copyright page of the book (at least in a print format). I am not sure what to do about this problem other than to make sure that authors pay attention to the contract when they sign it, so that if they are approached about reusing their work they understand what they rights situation is. I think this is an issue with copyright statements in books in general. Copyright agreements are often complex, and ownership of the copyright, as opposed to ownership (temporary or permanent, exclusive or non-exclusive) of various rights therein, is not that relevant to the question of a right to republish or reuse.
(I made a follow-up to this point on February 21st, 2016.)