An escaped quote character is interpreted as end of string, causing mis-matched strings and comment end (and other bogus error messages that fall out).

Example in a css file: 
    (
     line numbers added at beginning of line, but not a part of file contents!
     -so the first 4 characters are not content [num-num-num-space]
    ):

001 /**************************************/
002 .comment-in-quotes-with-escaped:before {
003  content: '/* \" \' */';
004 }
005 .this_rule_must_stay {
006  color: #F00;
007  background-color: #FFF;
008 }
009 .comment-in-quotes-with-escaped:after {
010   content: "*/ \" \ '";
011 }
012 /************************************/
013 /*
014 "This has to go"
015 'This has to go'
016 */

For above, on line 3, the second quote (') is interpreted as end of string, rather than an excaped quote.
After that, the editor then thinks the asterix is an unexpected character, and the last quote on line 3 comments out everything until the last quote on line 15. Line 16 is also seen as an error.

The escaped quote must be allowed, or the CSS would fail on the site.