Program logic bugs vs input/environmental errors

[Walter Bright via Digitalmars-d]

On 10/20/2014 1:54 PM, Timon Gehr wrote:
> On 10/18/2014 07:40 PM, Walter Bright wrote:
>>
>> As I've said before, tripping an assert by definition means the program
>> has entered an unknown state. I don't believe it is possible for any
>> language to make guarantees beyond that point.
>
> What about the guarantee that your compiler didn't _intentionally_ screw them
> completely?

What does that mean?