It appeared that Donald only gave to vets after the media pushed the issue, demanding verification; he claims that the proceeds of his book sales will go to charity, and the law may demand verification.
"If Donald Trump’s claims that certain of his commercial ventures benefit charity are untrue, he could be held liable under Section 349 of New York’s General Business Law, which forbids deceptive business acts and practices, as well as under charitable solicitation laws, according to legal experts.
"In promoting products as varied as Trump University, Trump Vodka, a Trump board game and his latest book, “Crippled America,” the businessman has declared that the proceeds would go to charity. None of Trump’s proceeds from Trump University have gone to charity, and only a few hundred dollars of charitable giving related to Trump Vodka has been accounted for. News organizations have been unable to verify his other claims, and his representatives have been unwilling to provide more information about them or even to confirm them."--Ben Shrenkenger, Politico