I suggest the same improovment that found its way into radiator plugin - requested in http://issues.jenkins-ci.org/browse/JENKINS-6507.
Excerpt from radiator version Changelog:
JENKINS-6507: If the claim plugin is installed, claim details are shown with broken builds. "
Claiming is very useful feature on failed builds.
On the other hand, I like the way xf indicates who is responsible : displaying the person's name BIG and UNIQUE ! I would prefer to stay with displaying only one single name - that would be changed over time by using claim feature. Strategy would be: if no one has claimed the failed build: display the first person who commited after last successful build (even over several failed builds), if someone has claimed the failed build - display claimed person's name.