The Dogs Bark, But The Caravan Goes On...
Wow, this escalated quickly.
This is my 2 cents, and I could be wrong.
I have 2 bachelors degrees (Network Engineering Management and Computer Science), every ISO certificate achievable in my discipline. I've been in the tech field for 25 years, have held every position up to my current (VP of Cloud Innovation) including the fun ones (Pre-Sales Architect, Sr. Cloud Architect and Independent Infrastructure Specialist). I have developed, implemented and sold multiple REST API applications to large [unnamed] companies most of you probably use. So I know a little about 'puters. That being said, here is my synopsis.
I coined something when working for a large bank called 'The Abstract Probability-Possibility Matrix'. It uses data and a formula (which is now intellectual property so no, I can't give it out) to determine the likelihood of a condition being satisfied. I will loosely apply that here.
The possibility that he is the only one that cannot access the site is 100%. However the probability is significantly lower bordering on zero. It doesn't mean its not possible, but it does mean its highly improbable. And here's why...
The domain uses Cloudflare services. Predominantly a CDN (Content Delivery Network) a decentralized service to basically distribute copies of the site quickly and provide 10*n continuity. Its also used for things like DDoS mitigation, IPS/IDS and DNS registration. 10's or 100's of "nodes" around the world hold copies of the site. When its updated, all of the nodes receive a copy, but not in parallel every time or really ever. Some nodes will update immediately while others take longer. Minutes, hours, days even. It is quite possible the node his request was being routed to had issues updating or redirecting the GET message rendering a 404 (missing resource) or 403 (unauthorized). Point being the chances of the site being "down" is very slim. Could have been an issue with Cloudflare, which doesnt fall on the site developer, owner or host technically. It would fall on the services at the network layer (CDN, proxies, load balancer, etc) and that really fucks up the SLAs for the provider so they squeeze the cheeks so that doesn't happen.
Then there is a bunch of other factors to throw in there. Certificate validity (for a node or cluster of nodes depending on configuration), CDP availability, ingress issues at the provider level, all the way down to the device itself (stale browser cache, revoked cert, broken cert chain, etc)
Without seeing the device or the traffic analytics its hard to say. There are so many variables at play sometimes its hard to narrow down the root cause. Sometimes its as simple as being disconnected from the router, DDoS attack on your home router, browser extensions, browser hijack objects, etc. Or it could simply be a transient issue like a failover or squirrels on the line. It can manifest itself through any of these.
But the point im trying to make is...
If I can get to it, they can get to it and probably a vast majority of others, his 'puter done f*cked up. Doesnt matter how long anyone has been doing anything, technology just flipped you the proverbial bird.
Suggested remediation: Reboot, go to the gym and try your call again later. Message CI-2.
Servers and sites dont really "go down" anymore unless you are hosting them in your basement on a 20 yo Dell with zero continuity.
And Im damn proud to be a high tech redneck, so offend me not.
I'm not a judge, nor casting conviction but "being new" then immediately attacking a long-vetted source seems a bit, shall we say, shitty.
All in good fun guys