I prefer this way of writing such a condition (more "natural" to read)

```python
        if flag_instance.content_settings('NEEDS_TRUST') and not can_user_be_trusted(user):
            flag_instance.send_untrusted_warning_mails()
        else:
            flag_instance.save(send_signal=send_signal,
                               send_mails=send_mails)
```