Crushing the blacks simply refers to clipping the data in the low end of the image so that the grays and shadow area show up as jet black or 0%. In camera this can be done by raising the master pedestal, or it can be done in post using a color correction filter. The benefits, (As related to the HVX200) is that there is some noise that can reside in the low end and crushing the blacks will help get rid of it, keep in mind however you loose detail in those areas as you do that. Alot of people prefer to make this adjustment in post rather than in camera, usually trying to enter post-production with as much detail in the image as possible to give greater latitude for color correction etc...
Sorry I am such a new, but where do I adjust the pedistals. Only had my camera for 1 1 full day, Did some Water sprinkler footage at 720p/24pn 60fps looks sweet, so many dropletts. Also tried an setting called 180d in the shutter speeds just after 1/1000, but did not look much differnt, and I am surprised me dont get higher shutter speeds.