If they should credit everyone that did something that's used as a backdrop for a few seconds in a movie, they'd have time for little else. The guy who did a mural the main character walks by also doesn't get a credit.
http://www.hollywoodreporter.com/thr-esq/Maya-hayuk-lawsuit-...
I'm not saying I think he should pursue it in this case, just that the scenario you laid out isn't unprecedented.
The difference is, of course, that writing code is joy so no wonder people will gladly do it and give the results away, whereas creating art is unpleasant, tiresome work, so it's an insult to suggest anyone would do it for reasons other than money.