[jomar]

TFA is a war story about how infelicities such as caching in tools and “those darn browsers” contributed to the identification of the cause of this issue taking longer than it should have.

Once the missing intermediate certificate issue had been identified, the fix (to the server) was indeed clear. But it's not stated whether the author is in charge of the server in question (it's only mentioned as “couldn't connect to a particular HTTPS site”); I suspect this was some external web site not under their control.