Humans make mistakes.

I was browsing through the release notes for the Java 5 release 12 release notes and saw this on the list of bugs being fixed. And I saw this entry

6524112

tooldocs

all

sloppy developer missed testcase when fixing 6490790

http://java.sun.com/j2se/1.5.0/ReleaseNotes.html#150_12

Human make mistakes.