Fieldset disabled attribute and descendants

http://dev.w3.org/html5/spec/Overview.html#the-fieldset-element

In the description for the <fieldset> disabled attribute, the spec says:

"The disabled attribute, when specified, causes all the form control descendants of the fieldset element, excluding those that are descendants of the fieldset element's first legend element child, if any, to be disabled."

Is there a reason why the disabled attribute shouldn't also disable controls that are descendants of the first legend element? See the attached test case.

It appears that IE and Opera disable both controls inside and outside the <legend> whereas Firefox, Safari, and Chrome disable neither. Our preference would be to remove the clause "excluding those that are descendants of the fieldset element's first legend element child" from the spec.

Cheers,

Adrian.