Never trust Google with anything!
Google’s spam filter prevented her sharing the document. It did not lock her access to it. That’s a pretty big distinction.
That said, I don’t trust important things to these companies anymore. If the automated system so decides, you’re gone. Good luck getting your account and data back.
Not only that, but it had nothing to do with the content, and everything to do with how she was sending the link to loads of people (google said she was spamming, she apparently said she wasn’t, the top HN comment says sending it to alpha/beta readers though I didn’t see this mentioned in the article).
Them even having the ability to read the contents of your personal files is just so wrong to me, though I guess they never promised privacy.