The claim-plugin allows users to claim failed JUnit tests by clicking on the "claim it" link (on the test results page). This link doesn't work when the Build-Failure-Analyzer (BFA) plugin isn't installed.
The BFA plugin is an optional dependency of the claim-plugin so this isn't desired behaviour.

Without the BFA plugin clicking on the "claim it" link results in Javascript errors such as "Uncaught ReferenceError: ShowPopup is not defined".