I'm just now getting around to reading the T2 books written by S.M. Stirling. They pic up a few years after the movie T2 and have their own version of events leading up to a renewed skynet/judgement day. These were written before T3 was made. I rewatched T3 today and noticed there's some minor plot elements taken from these books.
So my question is, did S.M. Stirling get any type of credit or recognition or payment for the ideas they took from his work?

being almost finished with book 3 I wish they had made a formal agreement with Stirling and made T3 and T4 be direct movie versions of the 3 books

I doubt it. Most likely, the production company owned the intellectual property, not Stirling. Same thing with Stan Lee - he doesn't have to get credit for the Superhero movies with characters he had a hand in creating. Marvel owns the property. He recently sued over this.

Terminator flickmakers haven't been known to credit those they were ripping off, anyway...

At least not at first.... Right, Harlan?

Hence the mention.