Define "correctness bugs". Does the code leak memory (which is not ideal)? That's only an issue for the scientist if it prevents/invalidates the science. But if the pattern hides how something is expressed, or someone unfamiliar with the science tries refactoring the code, that's more likely to cause issues with the science than the memory leak.
> Access all over the place – globals/singletons, "god objects" etc.
Crashes (null pointers, bounds errors), largely mitigated by valgrind/massive testing
Complete lack of interest in parallelism bugs (almost fully mitigated by tools)
