The parser seems to die if there is an open comment (<!--) within a script tag which is closed outside the script tag. See testcase. Originally reported at http://crbug.com/19356 (This is pretty major, but I'm not sure about severity levels here so leaving Normal)
Created attachment 38800 [details] Testcase
Happens on all platforms
According to html5lib, WebKit behavior matches the spec here. *** This bug has been marked as a duplicate of bug 16722 ***