This sounds like someone who's never worked on a large Python project with multiple developers. I've been doing this for almost two decades and we never encounter bugs because of mismatched types.

Have you worked on major projects in other languages in that time period to be able to compare and contrast?

The last two python projects I had to work on didn't have bugs because of type issues, but it was much harder to come into the codebase and understand what was going on given that you didn't have type information in many many places which forced you to go back and comb through the code instead.