He's mentioned on Dragon Talk and Dragon+ on many occasions that he's now much more careful about looking things up in the books, because he has so many different variations of the rules in his mind and wants to make sure he comments on the actual version of the rules they released.
The two parts I bolded are what I'm talking about here.
First, whoever designed the game-JC here-did not come down a mountain carrying tablets of stone with the 5e game system inscribed upon them! No, JC, and game designers generally, have gone through weeks, months, even years, coming up with ideas, rejecting some and keeping others, refining some, researching past rules systems (
especially true for D&D!), and having many different solutions before actually settling on one.
Then they publish The Book.
Then the designer
continues to do what designers do, which is to continue to think about these ideas and better ways to do them, sometimes utilising feedback on the actual play experience of others, and frequently come to think things like, "They don't seem to understand what I meant; I could've explained it better", "I didn't realise the ramifications of all those rules and one rule has had unintended and undesirable consequences; I wish I'd have done it differently. I should change it".
So, for the designer, their thoughts about a rule system are in a constant state of flux.
But for us, there is only....The Book.
We treat The Book like it was The Revealed Word. Which it literally is!
What it says in The Book about its own rules
must, by definition, be True.
But what if there are inconsistencies? Well, we could ask The Creator what he meant!
So we ask him.
First, because his own understanding of the rules has been in constant flux this whole time, it is easy to understand that his current understand is
not what The Book says. And that when asked on different occasions years apart, when his own thinking about the rules has changed over time, it's easy to understand how he comes to different conclusions. Not because he is stupid or drunk or bored or distracted, but simply that his thoughts on the rules, in constant evolving flux, has changed.
Even when The Creator goes back and reads The Book to check, the very fact that his understanding has changed may lead him to very different conclusions about
that same rule over a period of time.
But we only have The Book.
We cannot be privy to The Creator's thoughts, even as accessible as JC is on Twitter. We also cannot reasonably be expected to change the way our game works at exactly the same moment as The Creator changes his opinion on his own rules, which are now Set In Stone for the rest of us.
Because, make no mistake, when we go to our FLGS and come back with this brand spanking new 5e PHB,
we HAVE been to the mountain and come down with tablets of stone with the 5e game system inscribed upon them! ....Metaphorically speaking.
Sure, each table then sets up its own denomination, but most of us don't declare a Crusade against unbelievers....even though it might seem that way on the forums.
