Whilst I don’t have the typeface used
I would have broken the lines as follows:

I find a It was a crime of negligence, really.
A rookie mistake by a designer not bent
toward mayhem, but hurried to finish the job.
He simply hadn’t checked after full justifying
the paragraphs in the text. As a result, his
ignorance had created unsightly patterns
of white space that ran the length of the
pages in the document – rivers.

He could’ve easily avoided it all.
By taking some extra time to adjust his
hyphenation and justification settings or
choosing a typeface with different letter-
spacing the reader would be spared.
The ultimate fix to avoid such pain and
suffering? Rewriting the copy to fit to
the page.