Lam the manager, or the foreign purchasers? Who do you think has more power to improve things for the workers? Mr. Lam and the Western companies were equally at fault for the deplorable conditions endured by the Chinese workers in the film. The Western companies deliberately contract with foreign manufacturers to circumvent the very laws and public policies of their own societies that are designed to protect their citizens from exploitation in the workplace. Instead of accepting the natural limitations on profit that were possible in their own nations, Western companies chose to export their manufacturing operations to China where no legal or public policy restrictions were available to protect the welfare and safety of working conditions and where children were still routinely forced to work long hours at hard labor.

Obviously, Mr. Lam and other similarly situated Chinese nationals...

In many respects, the host nations could refuse to accept contracts that failed to pay at least what a fair wage would be in their own society and they could refuse to agree to any output requirements that required their citizens to work excessive hours or under abusive conditions. There is no reason that Western companies could not restrict themselves to the maximum profit that was fair and that did not require exploiting foreign workers. Likewise, Mr. Lam and other Chinese employers could have honored their moral obligation to be good stewards to their own people by refusing to agree to any contracts or terms that would require their workers to sacrifice their lives and their well-being for the sake of company profits.
References

Halbert, T. And Ingulli, E. (2008). Law & Ethics in the Business Environment.

Cincinnati, OH: West Legal Studies.

The Hershey Company. (2011). Our Story.

http://www.thehersheycompany.com/about-hershey/our-story.aspx