def parse_user_update_sync_agent_data(json):
    """
    Parse the incoming statement for a sync agent event concerning a user update.

    :param json: A statement concerning a user update that needs to be synced.
    :type json: dict(str, NoneType)
    :return: A dictionary containing all user information of the updated user.
    :rtype: dict(str, str)
    """
    statement = json['statement']
    user_info = statement['context']['extensions']['http://id.tincanapi.com/activitytype/update']
    return user_info