The account menu link (<a href...>) currently has role="button" & aria-expanded attributes applied.
First off, applying button to a link is against the 2nd rule of ARIA use - "Do not apply 'role' attribute where native semantics are available"

[[ http://www.w3.org/TR/wai-aria/states_and_properties#aria-expanded | aria-expanded ]] on the other hand, should be indicating "whether the element, or another grouping element it controls, is currently expanded or collapsed". [...] "If the element with the aria-expanded attribute controls the expansion of another grouping container that is not 'owned by' the element, the author SHOULD reference the container by using the aria-controls attribute.

From my understanding it's questionable to have it there or have it there on it's own. aria-controls sounds appropriate.