How can you possibly be this confident if you don't know the number of times Firefox was run and number of bug reports submitted? Say it's run 100,000,000 times, 1000 reports are submitted, and 10 are bit flips. Seems reasonable. You're misinterpreting what they are saying.
10% of 1000 isnt 10; its 100.And no, its not reasonable - the main reason is that you cannot reliably tell if something is a bit flip or not remotely, because bitflips affect both code and data. Also, 10% of a semi-obscure specific category of failures seems to indicate that the population submitting crashes isn't random enough. I'm a layman in statistics, but this doesn't seem correct, at least not without concrete details on the kinds of bugs being reported and the methodology used. Claiming 10% and being able to demonstrate 10% are different things - and the tweet thread indicates that is this clickbait - something in the lines of "may potentially be a bit-flip". Well, every error may be a bit flip.
