Isn't Kindle formatted in HTML? Probably someone dropped an HTML tag and didn't notice.
I do think it is this problem. I've come across it my self. They to test, if some else hasn't said it already: go back to before the problem, then use the GO TO to jump the text to a spot ahead of the logical end to the formatting issue. You can usually tell.
For example, there was a book that started with an epigraph of centered text poem, but the centering bleed into the text of chapter one. When I jumped ahead of the poem, the text was justified again.
And DO report the bad formatting to Amazon.