By putting this on Twitter, it immediately gets turned into something that could spawn clickbait headlines and could tarnish the company's reputation long term. Maybe John didn't mean for any of that, but his tweets don't mention the MIT licence initially and seem like they're building up an allegation.

I think Chris responded exactly like a for-profit company's CEO should, pre-emptively countering tech journalist headlines, clearly and concisely describing the situation, and still reaching out for the potential of collaboration.

There is no mention of O'Nolan being rude (although he did make a number of untrue claims, which at least pretty negligent—but that's not a charge that the linked tweets say, either...)

There was no code use, and there was no copyright violation/failure of attribution, so there is no "yes we use some code, oops we will add attribution" called for, nor would it even be logical to do so.