Build does not stop on Windows if there is a build failure on the AS and it is not a pull request

You can see the AS failed to build:
http://172.17.131.2/job/narayana-windows2008-taconic/415/console

I suspect it is something to do with:
call build.bat clean install "-DskipTests" "-Drelease=true" || (call:comment_on_pull "AS Failed %BUILD_URL%" && exit -1)

Maybe commit on pull is returning false because nothing is done?