Can an Attorney General's suit be defamation

I thought we’d seen the weirdest of legal counterattacks against Democrats states, but this latest one has me boggled.

https://www.nytimes.com/2025/09/01/climate/exxon-california-plastics-defamation-lawsuit.html?unlocked_article_code=1.jE8.tDNP.N6YLNmLUHNRg&smid=url-share

Did California’s attorney general and several other groups defame Exxon Mobil when they sued the oil giant last year over its role in widespread plastic pollution?

That was the question looming over a recent hearing in federal court in Beaumont, Texas, where Exxon Mobil has countersued Attorney General Rob Bonta of California and the nonprofit groups, accusing them of mounting a conspiracy to destroy its recycling business. Exxon’s aggressive move signaled a sharp escalation by the oil giant as it tries to ward off similar suits in the future.

This is not a personal, private comment but a lawsuit by a state official. How could any prosecutorial action be defamation? Wouldn’t that mean that any case lost by the state would defame the winner just by bringing it? Couldn’t Trump sue Attorney Generals* for the lèse-majesté of saying he’s committing illegal acts? How far do the ramifications of a court accepting this defense go?

* Not Attorneys General. I live in 2025.

I realise it is way too early in a thread for snark, so apologies for thinking this OP was referring to a petrochemical (nylon-based) suit.

Tan coloured, perhaps.