Such tests would fail without completing correctly, leaving the test appearing to be stuck in progress and never completing. This was not good.
Such issues are now recognised. If a JS static analysis test is run against a web page that links to a 404ing JS resource, such a problem will be noted and present in the results for the specific test.
As a bonus side effect, any non-200 HTTP status code encountered when trying to retrieve external JS resources (not including redirects) will be recognised and reported in a similar manner.