@trust is an encapsulation method, not an escape

[Vladimir Panteleev via Digitalmars-d]

On Friday, 6 February 2015 at 10:28:38 UTC, Walter Bright wrote:
> On 2/6/2015 1:01 AM, Vladimir Panteleev wrote:
>> On Friday, 6 February 2015 at 08:58:05 UTC, Walter Bright 
>> wrote:
>>> Cue my endless attempts to explain the difference between 
>>> input errors and
>>> logic errors :-(
>>
>> So which one is it?
>
> http://www.digitalmars.com/d/archives/digitalmars/D/Program_logic_bugs_vs_input_environmental_errors_244143.html

That doesn't answer my question.

A few years ago, I recall, you were arguing that for functions 
which are or may be exported to a DLL, thus all Phobos functions, 
it is impossible to predict how the functions will be used. Thus, 
you argued, the functions' input has to be validated, even if 
invalid parameters can only be passed to the function as a result 
of a program bug, and never user input.

So, to repeat my question: which one is it? Have you changed your 
mind, or are there exceptions to the rules in the post you quoted?