Background workers are geographically spread out across multiple AWS regions: https://tryhexadecimal.com/docs/workers#locations

It is highly unlikely that all of them will be knocked down at the same time.

If workers suspect that there is something wrong with your website, they will check it from all locations at once. Website is only marked as down if more than half of them can agree on that. That alone knocks down most of the false positives: https://tryhexadecimal.com/docs/uptime#sequence-and-frequenc...