“Of course I’m not in favor of slavery! But signing an agreement [with the Coalition of Immokalee Workers] does not actually change those conditions for farmworkers,” Steve Ells, CEO of Chipotle Mexican Grill, gibed in front of an audience of 250 at the University of Pennsylvania’s prestigious Wharton School of Business on November 19. “I mean, they just don’t see the bigger picture,” he continued. “To change the fast-food paradigm is huge. We’re trying to do the right thing.”

Ells’ defensive posture came in immediate response to a question posed by Marina Saenz-Luna, a staff member of Just Harvest USA, who works closely with the Florida-based Coalition of Immokalee Workers (CIW). Since 2006, the grassroots farmworker organization has petitioned Chipotle – a leading fast-casual restaurant chain specializing in gourmet burritos – to enter into an agreement to improve wages and working conditions for Florida tomato pickers. Four years later, farmworkers’ and consumers’ stomachs have soured in light of Chipotle’s persistent hostility towards the workers’ organization.

It didn’t have to be this way. Ells founded Chipotle in 1993 with an $85,000 start-up loan from his father. The venture has since bloomed into one of Fortune’s 100 fastest-growing companies with over 800 restaurant nationwide. Along the way, Chipotle has emerged as a self-styled leader in the fields of sustainable agriculture and socially responsible supply chain management through its highly publicized commitment to “Food With Integrity.”

Chipotle explains on its website that, “‘Food With Integrity’ isn’t a marketing slogan.” Rather, it “means working back along the food chain. It means going beyond distributors to discover how the vegetables are grown, how the pigs, cows and chickens are raised, where the best spices come from.” For his part, Ells, the chef-cum-corporate executive, reflects, “Learning about this dark side of modern agriculture made me want to find out how we could do things differently.”

Yet Chipotle has responded to the human rights crisis in Florida’s fields-including seven federally prosecuted cases of modern-day slavery since 1997-with silence, evasion, and cynical spin. And Ells seemingly has no compunction about using his high-profile speaking engagements to spread misinformation about the CIW’s Campaign for Fair Food and the impact of his company’s policies on farmworkers.