I can't (or, more accurately, don't) believe that, but I can certainly believe they have nothing interesting to say about the topic of static vs dynamic typing.
An open mind is like a fortress with its gates unbarred and unguarded.
It is both useful and allowed to have a certain level of belief that won’t be crossed without heavy effort. The OP didn’t even say they were closed to the conversation completely, but that a random person with no pre built trust isn’t going to get the time of day from them to rehash the same settled argument.