Frankly I don't think they actually learned enough!
But basically, when the rear-end hazard was found in the Pinto, the company made a decision that it would be cheaper to defend lawsuits than to fix the problem.
What they learned from the debacle was that negative publicity from the lawsuits can hurt them more than the cost of the lawsuits themselves.
In a sense, 'business ethics' is an oxymoron. Businesses are in business for one reason only--to make a profit, to maximize return on investment. Despite all that leaders of business say about providing public service, etc., the profit motive is the major priority. This is why businesses can't be just left alone to make ethical decisions, or to enforce ethical rules. It's one reason we need govt. regulation, including consumer safety infrastructure. In a way, you can't really blame Ford execs for making the decision based on maximum profit--that was their job!
This is why I often find myself in disagreement with Republicans, who believe that -any- govt. regulation is wrong, and with Libertarians, who believe that this should all be covered by Caveat Emptor. We need laws (and ENFORCEMENT) to insure that cars meet a minimum safety standard, just as we need them to guard against adulteration of food, drugs, drinking water, etc.
