[throwawaylinux]

That's not contrasting evidence. Defects are certainly common sources of error, particularly with cheap commodity components like those used in google's fleet. That does not prove cosmic rays aren't a significant source of SEUs [in any computing device].

[vlovich123]

No but it adds significant credence against the cosmic ray hypothesis. Particularly since this Mozilla blog post has lots of speculation without any actual data to support the claim.

FF is running on even lower cost commodity components without strict controls on the operating environment (eg environmental heat isn’t controlled like it is in data centers, power supplies can be borderline vs carefully species Google machines, etc).

[throwawaylinux]

It does not add any "credence against" the well established fact that cosmic rays flip bits at significant rates that it has to be designed for.