There is some variation across the English speaking population including a variation often used by African-Americans. Theses differences are found in such things as the acceptability of double negatives or regularizing irregular verbs. Look up AAE or AAVE. There are differences to which one should be sensitive, but this is NOT one of them.

In this case, this is an error you find more in people who are educated and pay close attention to their grammar, such as the president.