"Negative caching was an optional part of the DNS specification and deals with the caching of the non-existence of an RRset [RFC2181] or domain name."
Optional.
Now, I know how DNS works and so do you but your average sysadmin wants instant results as they thrash around trying to get something to work. You see the same effect with firewalls. If state tables don't get flushed after a change then the change will seem to be ineffective. Been there and done that. States often die after five minutes and so do Windows DNS fuck ups.
That is why the master says: "wait longer" followed by "turn it off and on again" or "go out and smoke a fag" or "get me a coffee" or whatever. When your arse is on fire in IT, learn when to trust your judgement and take five.
So you fire up cmd.exe and issue ifconfig /releasedns, ..., ipconfig /?, ipconfig /flushdns and then you go back to pinging the bloody address instead of using nslookup because you learned from another idle/jaded sysadmin to use ping as a shortcut to querying DNS, instead of actually querying what the DNS servers respond with.
Obviously, a better thing to do when checking your DNS entries is dig out ... dig.
DNS changes _do_ propagate: from the one you edited to the others via zone transfers and the like (primary to secondary etc) and thence to caching resolvers.