> Using open-source Chromium instead of Chrome did not cause crashes, so we couldn’t see what Chrome code was failing either.

They don't address why they didn't just run Chromium. Or Firefox.

(This is potentially better than the 'solution' they much later ended up with, in which they probably only relieved a symptom of an underlying problem that can exhibit again, and in the meantime is a zero-day exploit waiting to happen. At least, with a different browser, there's a chance that the vulnerability doesn't actually exist, when it's known to exist in their Chrome configuration.)