either they lied about where they resided and just put in a U.S. address or it was for the additional child tax credit which is UP TO $1000 per child- depending on amount of income.
The people that were coming from E'Y was not for ECI, it was for additional Tax Credit (If they had 7 kids that's $7,000 per year and file for the last 2 years also, that adds up to $21,000)