I'm OK with a Congress that took away billions in funding from ACORN because of their blatant dishonesty and lack of ethics.
I'm OK with the U.S. Census Bureau's severing ties with ACORN and not letting its members participate in (and corrupt) the U.S. census.

You are looking at a minor infraction by O'Keefe where one ACORN individual filed a case against O'Keefe and he could not disprove the allegation. Perhaps the ACORN guy was a corrupt thug like the rest, but O'Keefe simply could not prove it. That does not disprove what every other major media source has acknowledged as fact about ACORN, despite an error on a minor footnote by O'Keefe.