The FDA released it's report on the Jensen Farm Outbreak.
"FDA identified the following factors as those that most likely contributed to the introduction, spread, and growth of Listeria monocytogenes in the cantaloupes..." (click link above to read full story).
With a few exceptions Jensen acted within industry norms. It would seem necessary to take a few extra steps with cantelope production. For instance, like the production of eggs. A wash cycle then air dry racks with continuous air flow before going into package for storage area to distribution.
In some places though it seems to be more a case of following through with HACCP programs then adding a few extra steps (i.e. pools of water and cattle trucks parked near the packing facility).