Which is why Buddha is casting as many aspersions as possible on scientific realism. And why he formulated his "proof" as little more than a contrived thought experiment, not with any actual evidence or reference to knowable fact. He did say at one point that he could provide "empirical" proof of God, but I'm beginning to believe that he's just throwing out buzzwords from science and philosophy without really knowing what any of them mean. He equates "unfalsifiable" with "false," for example.
His strategy is to note that some of his critics are indeed relying on scientific realism to affirmatively refute his proof. And to them he claims to have so much better understanding of the various competing philosophies that could apply, and simply declare realist rebuttals categorically wrong because what's dreamt of in his philosophy is so much more academically appealing or in vogue. It's like saying your apple pie isn't really apple pie because banana creme pie is so much more enjoyable. He admits up front that not everyone will accept his proof. But that merely steps into his next argument, which is that if you don't accept his proof you're just not as philosophically sophisticated as he. Because he read a book a few months ago, you know.
But not all his critics follow that pattern, so his answer above is little more than a straw man. Some of his critics, myself included, also point out that he's really not getting the other philosophies right either. His proof is a mish-mash of poorly wedded tidbits borrowed and misrepresented from various disciplines or invented out of whole cloth and wrongly attributed to great minds. He ignores such criticism because in order to refute it he would actually have to demonstrate knowledge of the fields he's raided. And this he cannot do, so he continues gaslighting and chest-thumping. His proof isn't intended for knowledgeable eyes, apparently. It seems more intended to fool some naive third party into being impressed.