My sister-in-law teaches English in South Korea, where grades are even more important than they are here to a child's future, and cheating has even graver consequences (entire college career, and thus their future in knowledge jobs are gone).
Yet, they still cheat.
Perhaps I'm just being pessimistic, but I don't believe that 200+ students believed they just had study material. I believe they knew they were cheating; else you would have had at least 1 of the 200 step forth and say "You know, this is identical to the study material I received from my friends...". Even the person who did eventually clue in the professor did so anonymously by dropping the complete test script in his office.
Of course, blaming this on the professor seems overly optimistic about the state of mind of those 200 students.
Either way, I would not want one of those 200 students working for me. If they don't have the moral fortitude to admit that something is wrong on a test in college... I can't imagine what they could do to a company where moral standards are core to a companies very survival; such as a company which handles customer credit data where a single leak of customer data can sink the company.