I believe the "plan" was to sink her slowly by letting some water in, then have the "safest" at sea disaster by calling for help with enough time for nearby vessels to assist. The theory then goes on to claim that hitting the iceberg was an accident that only happened because they couldn't steer around it fast enough due to the water they had already taken on.

Can't remember where I read this it, might have been the Wikipedia article about the conspiracy theory.