Also, the book makes it clear that Nedry isn’t just some greedy asshole, he’s someone getting screwed over and financially ruined. Hammond hired him as the lowest bid for the job of setting up the systems, with a contract that explicitly stated that support was not included, only for Hammond to threaten to sue him until he goes broke and ruin his reputation so no one else will hire him unless he provides free support. He’s being dragged to the island and working around the clock and he’s not even getting paid for it. Of course he’s going to take the opportunity to get paid for screwing over Hammond.
Also, the book makes it clear that Nedry isn’t just some greedy asshole, he’s someone getting screwed over and financially ruined. Hammond hired him as the lowest bid for the job of setting up the systems, with a contract that explicitly stated that support was not included, only for Hammond to threaten to sue him until he goes broke and ruin his reputation so no one else will hire him unless he provides free support. He’s being dragged to the island and working around the clock and he’s not even getting paid for it. Of course he’s going to take the opportunity to get paid for screwing over Hammond.