I believe that's a reference to Tony Hoare's famous talk about the invention of null references which he calls his billion dollar mistake https://youtu.be/ybrQ

I believe that's a reference to Tony Hoare's famous talk about the invention of null references which he calls his billion dollar mistake https://youtu.be/ybrQvs4x0Ps https://youtu.be/ybrQvs4x0Ps