Download file from link in data model is failing

An external user has notified us of an error when trying to download a file directly from a link in the data model.
This is a "Data Delivery" workspace created by the pipeline ops team and the Data model is populated with links to the cram files in the google bucket.
Clicking on the link brings up this dialog (trimmed to relevant part):

By following the instruction "right-click to download" and then selecting in chrome right click menu "save link as"... a file is downloaded but it is not the expected cram file but rather some json or javascript. The first few lines shown here:
{ "statusCode": 500, "source": "FireCloud", "timestamp": 1537208144030, "causes": [], "exceptionClass": "java.lang.NumberFormatException", "stackTrace": [{ "className": "java.lang.NumberFormatException", "methodName": "forInputString", "fileName": "NumberFormatException.java", "lineNumber": 65 }, { "className": "java.lang.Integer", "methodName": "parseInt", "fileName": "Integer.java", "lineNumber": 583 }, { "className": "java.lang.Integer", "methodName": "parseInt", "fileName": "Integer.java", "lineNumber": 615 },
...

I believe the ability to right click and "save link as" used to work to download files in this way. Is this still the intended behavior?

Thanks,
Jim