Hey, Luke, if you were in the same situation as Ethan & Jenna and still had money left, do you think you would have lied to Phil about giving away all of your money?
It seemed like the donation task was entirely contingent on the honor system. I don't know how production could actually confirm that every team gave every penny that they had to the orphanage. Even if they emptied every team's belongings and had every team strip naked and gave everyone a full body search, it still wouldn't be foolproof.