How Do We Trust Our Science Code?

Let's not forget how far off the Imperial College model for the current pandemic turned out to be. This model was accepted without reservation by governments around the world as the basis for their pandemic response.

Avoiding these types of errors might be difficult but how much effort are we really putting in trying? For one of my EE courses at university, I designed the power distribution system for a residential subdivision, aiming to keep all the voltage and amperage without acceptable tolerance while minimizing the cost of materials. The analysis was required to be done twice by completely independent systems. Seems odd that we are willing to make such huge decisions about the course of action we take without requiring multiple independent evaluations.