> If it turns out that there's an undiscovered recessive gene for lead hyperaccumulation in the cinnamon tee and that tragedies like this are how it gets discovered

That's not what happens though, lead poisoning in spices is ~always shady actors adding pigment that's lead-heavy to make the spice (for example, cinnamon, turmeric, ground ginger, paprika) appear more vibrant in color. The Indian government did a whole bunch of work to fight against this a few years back; ultimately it's suppliers trying to adulterate their product to save money and make it look better than it is. This should absolutely be a serious crime, on the level of intentionally shipping any other dangerous product: jail time for executives, huge financial penalties for companies.