I've just come across some unexpected behaviour.

When using the people update API to update a precinct_code, e.g. with the payload:

{'person': {'precinct_name': 'Burton Bradstock'}}

I received a "400 Bad Request" with the response

{"code":"validation_failed","message":"Validation Failed.","validation_errors":["email '[email protected]' should look like an email address"]}

The same thing happened with imports that didn't involve email addresses failing because of email validation errors.