I do CFD, so let's take that example, and say you have a bit flip in one value in one of your fields. There are four cases to consider:

a) bit flip happens so high in the mantissa it makes your code crash. detectable, you run simulation again

b) bit flip happens somewhat lower in the mantissa, enough that it shows up in your analysis. detectable as unphysical result, you run simulation again

c) bit flip happens even lower, you don't catch it as unphysical in your postprocessing and analysis. Here's where I'm saying: if a bit flip happens like this and affects your simulation in such a way that you don't see it's an error, but it still changes your end result and conclusion, and you're not running replications of your simulation to test robustness etc., you're Doing It Wrong.

d) bit flip happens even lower, same order of magnitude as numerical errors. nothing bad happens