"In any case, even a "friendly fire" injury can qualify for a purple heart "as long as the 'friendly' projectile or agent was released with the full intent of inflicting damage or destroying enemy troops or equipment," according to the website of the Military Order of the Purple Heart. All agree that rice was being destroyed that day on the assumption that it otherwise might feed Viet Cong fighters."
http://factcheck.org/article.aspx?docID=231