Using Null coalescing operator on LINQ Method still shows prompt for ArgumentNullException.

[DonaldRecord]

Without using the null coalescing operator in C#6, Exception shows me "Add documentation for ArgumentNullException" for the following code, which is good:

var results = GetAListSomewhere();
var result = results.FirstOrDefault(); //<--- PROMPT HERE
return result;

However, the prompt is unnecessary here, as the method would not be called.

var results = GetAListSomewhere();
var result = results?.FirstOrDefault(); //<--- PROMPT HERE
return result;