A Matter of Style - End Quotes Missing

[Steve]

Someone on the other list mentioned some typos and other errors in
HBP, which reminded me of something I've noticed in several books;
missing end quotes (ending double quote marks).

They usually occur in this form... (the text itself is meaningless,
concentrate on the form)

- - - - - - - - - - - - - - - 
"Some one is speaking. They talk and talk and talk. They ramble on and
on. Then the paragraph ends. [the end quote is missing]

"Then the next paragraph starts with the same person talking, and the
person talks and talks and talks." [end quote mark is there]

/narrative starts/
- - - - - - - - - - - - - - - 

Is this just a random error or is this a valid style of writing?

Just curious.

Steve.bboyminn