Hi Tim,
Maybe the adaptation for OutSystems don't use all codes from the original Library.
Is possible that the way it was implemented in OutSystems use some custom validations, since it was not a requisite back there to the developer to use all codes.
Looking for the post you linked from github, seems like this table of codes is not an original documentation, it is just a sample that some user provided, it may even exist more errors and scenarios than the ones listed, if I understand correctly.
Any way, maybe the reason the code 1 is not considered in the component as a valid return is that some part of the file could be missing due the failed requests.
You can always customize it for your needs if you want to add code 1 as a valid return.
But is also cool to wait for the feedback of the component's developer.
Cheers and Regards,
RR :)