Actually, that's not quite true. The WebKit prototype *does* throw when .responseText or .responseXML is accessed, but .responseType is not compatible (for example, "arraybuffer", or "blob")
> IIRC, in our current experimental implementation accessing > .responseText and .responseXML *never* throw based on .responseType - > they're just empty if .responseType is wrong for them. > > ~TJ >