You can't both write to the out stream and send a "sendRedirect".
In other words, if you're going to use sendRedirect, don't write anything to the page first (including a content-type header). Also, as a rule of thumb, you should have a return statement just after the sendRedirect.
The question on everyones mind should be the following;
Given that all other things are equal, and If you are using the HttpServletResponse object to redirect users, are your applications also failing for clients who uses Juno browsers to access your applications?