When NATO destroyed a Gaddafi family home on the night of April 31, killing three babies and Gaddafi's 29-year old son while narrowly missing the leader, it was a C3 center and who knows why or if the Gaddafis were there. A barracks hit in Tripoli's Tajoura district a month earlier was within a residential neighborhood, and reportedly killed 40 civilians.
If we accept both NATO's versions of these and other attacks, and the civilian deaths reported, the government complexes hit frequently have war-control facilities right next to or inside of homes, hospitals, schools, and sewage treatment plants.
They're hit anyways, damaging these civilian facilities over and over, with NATO always voicing regret for any civilian deaths that may have happened, and promising to "look into it" (it's the last we ever hear).
Considering this pattern, would Gaddafi find it a deterrent to run military operations from a building in Brega, and use the same place to house these pilgrims? He might possibly try, but again, it shouldn't be expected to work. NATO has only to fail to verify the claims, and they can be considered irrelevant.
If not a deterrent, perhaps he set things up this way as a trick - a human sacrifice to give NATO a black eye. This is just the kind of thing they're accused of frequently, and they are using the Brega strike for PR advantage against the "barbaric, inhumane NATO."
But really, they have plenty of excellent gripes already that have had little effect, and they stood much more to gain from a successful peace mission.
That would be quite a thing to throw away on more Gaddafi "human shield" brutality against his own people when any random religious leaders not engaged in something important could be slapped into some secret command bunker to similar effect.
Did NATO know anything about the clerics and the mission they were on?