It's unclear what you're even arguing for. Naive falsificationism? Even Popper didn't argue for that.

Science works by building theories and programmes of research. A single counterexample, contrary to what you seem to think, doesn't invalidate a theory--it's driven by multiple lines of evidence. And ESR's strategy of digging through comments of source code to quote out of context fragments doesn't even approach providing a single counterexample, particularly when he admits that he's in a quest to show that climate scientists are a conspiracy, part Gaian-religionists and part KGB psyops. Like, really.

You wrote "forcing him to make concrete predictions".

I took that to mean that you considered his criticism of climate models to be invalid because he hasn't produced better models himself.

Perhaps I mistook your meaning.