Well, since I mentioned it, here are two times POV (in 3rd person limited mode) can be violated, and they both are are the bookends of a chapter.
1 - At the beginning of the chapter, an author can slip in with an ambiguous POV - that is for a brief time (and I mean brief), while the reader is settling into the chapter (which might even settle in 2nd person for a paragraph, especially if its descriptive), an author can fudge POV and then - Wham! - nail it.
2 - The afterglow of a chapter, when a the POV character has left the premises but the story hasn't, you can get away with a brief slip into a remaining characters POV (and not a thought or stereoptic, but a casual and clever reference). For example, in my book The Jade Owl, the POV character leaves a restaurant, but is then observed by the waiter from the restaurant's window to close the chapter. (The waiter is a villain). Care still must be observed. I use the phrase, "if Rowden had stayed he would have seen Sam Chang watching him from the second story . . .etc. etc."
There are other instances. But under no circumstance should a reader be aware of these things. POV is a device best hidden. It only raises its ugly head when violated or ignored.
Edward C. Patterson