The difference might be due to Google A/B testing their algorithm. That is, giving users different results for the same query trying to infer which results were preferred based on whatever happens next (user keeps searching, or user goes and stays on some site).
Ignoring full page replacements ('Showing results for "eggzactly that", to see results for "eggzackly that"...) I think this is all just punctuation related.
For instances, on the ["quotes don't give"] example, the first result I get is
Thanks to the wonders of tokenization, that "don-t-give-up-quotes, don-t-give-up-the-fight" gives you the string of tokens, "don t give up quotes don t give up the fight", which contains the exact phrase "quotes don t give", which is the tokenization of the phrase "quotes don't give".
That's actually from the visible text of the page -- well, desktop version as I saw it; when you click through on mobile they only show half as many quotes and you need to load more to find it.
