Section 6.2.6 contemplates the case where a X-YADIS-Location header exists and a HTML tag also exist.
We feel strongly that the header if present should always be used, regardless if there is a and/or the value differs.
This approach makes the behavior when processing the results of both HEAD and GET requests consistent. If a GET request prioritized the tag, it would be prioritizing information not available to HEAD requests. It seems highly desireable to make the two as consistent as possible, which means prioritizing the HTTP response header.