LA Bid law says you have to go with the lowest responsible bidder. Responsible often means all of your paperwork is filled out correctly.
The implication here, is that sometimes the politicians let a particular bidder know that he can come in low just to win the bid, then they'll change the terms of the contract afterwards so that it is more profitable.
For instance, a large contract to outsource OGB is being worked on. The intended winner is BenefitFocus, but the RFP hasn't even been made public yet. They will be the low bidder.
This sort of thing is normal in Louisiana and Chicago, but Cazayoux will need to establish that either Greenstein, Jindal, or the GOP benefitted directly as a result of the bid-rigging. I doubt Jindal is that sloppy.