User blog comment:Tommy,Klaus&Kol2012+/How to Kill a Levithan/@comment-168.16.130.206-20120228000339/@comment-76.212.204.190-20120228093848

As Crowley clarified in "Abandon All Hope..", he has no loyalty to Lucifer. Futhermore, Crowley became King of Hell after the Apocalypse was averted, so he would have sent Meg to asist Cas as test of loyalty to him, not Lucifer.