During the initial tour of Jurassic Park in a scene in the command center John Hammond and Dennis Nedry have the following exchange:
Hammond: Dennis, our lives are in your hands and you have butter fingers?
Nedry: I'm totally unappreciated in my time. You can run this whole park from this room with minimal staff for up to three days. You think that kind of automation is easy... or cheap? You know anybody who can network eight eight connection machines and two million lines of code for what I bid for this job? Cause if you can I'd love to see them try.
Hammond: I'm sorry about your financial problems Dennis, I really am, but they are your problems.
Nedry: Oh you're right John, you're absolutely right, everything is my problem.
Hammond: I will not get drawn into another financial debate with you Dennis, I really will not.
Nedry: Been hardly any debate at all.
Hammond: I don't blame people for their mistakes, but I do ask that they pay for them.
So it sounds like Dennis is a contractor who put a lump sum bid (or perhaps very low hourly rates) in to get the work at the park... but why would John "Spared No Expense" Hammond just go for the low bidder? Why not negotiate with Nedry to make sure he is well compensated so that he is not disgruntled? Or was it perhaps something to do with this mistake that must be paid for?
(I forget if Nedry took the job to steal the embryos before or after his being hired by the park, or if he took that offer because he was unhappy with Hammond, but that might help explain things...)