I see your point, and it's a valid criticism of my statement. I meant it more in the sense that the static checkers I have used would use hackish ad-hoc heuristics which did not work very well, and gets constantly tweaked by the implementor.

The D implementation, in contrast, uses a well-defined rule outlined above, and it works predictably and reliably (absent implementation bugs, rather than ad hoc rule shortcomings).

Another way of putting it is that the rules of the language are changed to make 0%/100% results workable. The compiler never says "there may be a problem here". It passes or is rejected. If it is passes, it is memory safe.