that last part is extra important. nearly every one of these produce outbreaks are because of poor hygenic practices on the fields, and particularly, because field workers do not have adequate access to bathrooms. nobody wants to poison your food, but they often don't have a choice.
they also often lack proper access to water, cooling equipment (such as sun hats and portable fans), and management; this can make it significantly harder to think clearly and make a wise decision, let alone survive the day.
when this comes up in conversation, call this out. make sure everyone around you KNOWS that the reason the lettuce is constantly unsafe is because farms are not giving a shit about worker welfare, and the people growing and picking your lettuce have to walk ungodly distances in 100+ degree weather without water just to take a shit. oh, and if they DO choose to do that, they may be punished for taking an unscheduled break.