wow, alyoung, this a rough way to start out
though some may have gotten by (for now, anyway) with a flush & bypass (or a flush & new radiator), i don't think it will work in the long run
probably contamination amount, time, and mileage with that condition will determine that
also, how thoroughly you get the contaminated fluid purged out of there may have an influence on the long term
i could not find any TSBs on this issue, which does not surprise me in that Nissan would probably not like to acknowledge it on paper
did you buy it from a Nissan dealership?
did you get any kind of warranty (hopefully written) with the truck?