Since the guys who wrote the original code are scientists or engineers, they probably learn new tricks all the time within their own profession. The fact that they realized that their code has become an unmaintainable mess and have hired a software developer to help them out seems to indicate that they might be open to listening to what he has to say.
If the software guy comes in and starts insulting the scientist guys' code, the game is over. If the software guy shows no desire to listen to what the scientist guys have to say, or learn anything about the problem domain, the game is over. But if the two sides can learn to work together toward a common goal, they might have a chance of success.
If the software guy comes in and starts insulting the scientist guys' code, the game is over. If the software guy shows no desire to listen to what the scientist guys have to say, or learn anything about the problem domain, the game is over. But if the two sides can learn to work together toward a common goal, they might have a chance of success.