Strange to see Anthropic making this point. When I use Claude in my daily development and ticketing workflows, it doesn't seem to want to do formal verification of anything without me telling it to. It makes a lot of assumptions about the state of systems when it could very quickly write scripts to formally validate those states.
It's why unit tests are worthless when humans write them, and less than worthless when AI writes them. Same concept: you're testing yourself, of course you're going to pass with flying colors.
If you want it to do that consistently why can't you put it in your Claude.md?