I try to keep from rushing to judgment, but in the case of Lenore Hart's The Raven's Bride vs. Cothburn O'Neal's The Very Young Mrs. Poe, I'm inclined to go with "Guilty, guilty, guilty". St. Martin's must assume they don't have to pull a book when a dead writer, who is not likely to sue, has been plagiarized.
A CBS account has this:
In an interview in May with the online magazine www.bookslut.com, Hart acknowledged reading O'Neal's book, but only after she had turned in a "corrected draft" of her novel."I was engaged with it in some places and bored in others," she said, adding her "apologies to the late Mr. O'Neal."I'm guessing she was bored with the parts she didn't use in her own book.