Currently, the error says:
"2 : Unknown error, Stream was not read - on page 1"
So while the validation doesn't really need to bother with the "EOL encountered in white run", the pdf/A apparently contains further attributes such "/length" that can no longer be confirmed or denied.
1) the error should explain that.
2) If there is even not only a total length, but a specific length expected for the COSStream, error should mention that among others