Antonyms for the phrase "had part in" include "did not participate in," "was not involved," "was uninvolved," and "had no role in." These antonyms suggest a lack of participation, contribution, or responsibility in a particular activity, event, or decision. In contrast to "had part in," which can connote a level of responsibility or influence, these antonyms imply an absence of impact or influence. Depending on the context, using these antonyms can help to clarify the extent of an individual's involvement or lack thereof, and highlight any discrepancies in perception or expectation.