Question about proper use of screen readers in 508 testing

Hello,
I'm new to the discussion list and have a question about how much reliance
should be accorded to screen readers like JAWS when reporting accessibility
issues.

We have an internal testing team that uses JAWS for 508 testing. They are
reporting accessibility issues in cases where JAWS reads all the content on
screen, but does not recognize certain expand/collapse widgets as clickable
links.

In a different case, they have filed a "critical" bug in cases where a
button is read as "button button." Using the button is no problem; their
argument is that the duplicate listing is potentially confusing. I say
that's a usability problem, not an accessibility issue and thus not
critical.

My concern is that the testers are testing to the tool, not to
accessibility guidelines. Am I mistaken? Is there any guidance on how much
to rely upon a tool? Is there anything in WCAG 2.0 that speaks to this
issue?

Mike

Scrum Master
GrantSolutions.gov