"Ya Don't Tug on Superman's Cape"

As I'm sure readers of this blog already know, "From the Sorcerer's Scroll" was the name of Gary Gygax's regular column in the pages of Dragon. It was here that he would share previews of upcoming AD&D rules additions and changes, as well as offer his opinions on various topics of the day. Those opinions were often controversial, particularly when they pertained to the "right" way to play Dungeons & Dragons and generated a lot of pushback in the letters pages to Dragon. In retrospect, I wonder if that wasn't part of their point.

The column that appeared in issue #27 (July 1979) is quite unusual, because Gygax turns it over Bob Bledsaw of Judges Guild. Bledsaw uses the space to offer up a "personal opinion," entitled "What Judges Guild Has Done for Dungeons & Dragons." It's a fairly interesting read in its own right, but there's a short section toward the end of the piece that I want to highlight in this post.

I find it remarkable that, while Bledsaw praises uniqueness and originality in one's own campaign, he also suggests that rules changes, especially those relating to "play balance," run the risk of changing the game so much that one is no longer playing D&D. This is the position Gary Gygax himself advanced in many of his "From the Sorcerer's Scroll" columns and elsewhere. Agree or disagree, there's a logic to it and I suspect that Bledsaw, whose company produced official D&D (and, later, AD&D) materials under license from TSR, knew that this was a line he had no choice but to toe.
After that, Bledsaw then gives an example of when Gygax corrected him regarding rules changes he was using in his own campaign. This concerned the "instant kill rule (20 … 19 or 20)." What's he talking about here? No edition of D&D with which I am familiar has an instant kill rule, let alone the one he seems to describe. On the other hand, Empire of the Petal Throne does and the rule Bledsaw mentions seems almost identical to it. Is this the rule Bledsaw meant? Had he imported the EPT rule into his home campaign? If so, why did Gygax care? I understand that Gary strongly disapproved of critical hits, which is fair. However, if Bledsaw was using them in his home campaign, what difference did it make? So long as he wans't importing them into Judges Guild D&D products – and he says he was not – I don't see why Gygax should "call [him] on this very subject."
Have I misread what Bledsaw is saying?