MickeyD's just stepped in it bigtime.
The Hmong people earned a special place in the hearts of American combat soldiers because of their strong support for the United States. The VC and NVA were quite scared of them (not unlike reactions to Gurkhas). Their role was a secret in the early stages and they made a huge sacrifice to help the US. 18,000 of their soldiers were killed in battle before 1969, and more than 100,000 Hmong were killed by the time the U.S. made the decision to pull out of Vietnam.
Assimilation in the US has been difficult for them, being mountain people (independent minded, like our mountain folk) thanks to morons here who do not know the debt we owe them. And now this idiotic advertising. Did McD's even consider getting someone who spoke Hmong to compose the ad or did they go to some school or the internet?