Some CloudFlare presented sites will present a 503 response with a javascript challenge before presenting the site, which makes it difficult to interpret results.
If a site is using cloudflare (or a similar proxying CDN) we should record that anyway (and probably surface this at some later point)
If a site is using cloudflare and we can detect that, we should surface that information as the result instead of the "Error" "SSL Error" or whatever.
Some CloudFlare presented sites will present a 503 response with a javascript challenge before presenting the site, which makes it difficult to interpret results.