I agree that some are in denial of what records may prove on their family. I have also met people who want to prove something that just does not exist and will go to extremes of making up things. And sometimes things are true and just can't be proven because there is not enough evidence.
With my ancestors they may have been asked to be put down as white. I can't say for sure. All I do know is that my ancestor asked for immigration in the 1880's and was granted immigration in the US from Mexico. He could not tell a judge in TX in 1880's he was Indian. This was not safe!!! He claimed Mexican as his race. What I dont get is most of the Mexicans are Indian but if your Mexican Indian you were able tobe a citizen of the US but American Indian's were not permitted at this time to be citizens of their own land and country.