Says who? Says where?
WWW: A missile strike is not something you take into account when designing your 7E7 or A380. I'm sure the relatives of those lost on Korean 007 and Iran Air 655 will be able to tell you that.
I'm sure the outcome of that particular DHL flight would have been a whole lot different had the IR-guided SA7 not hit the tip of the left wing but one of the engines, the tail or the pressure cabin instead. Nontheless, the crew did an excellent job on saving themselves and the plane against all odds, and I hear the A300-600F in question is in fact scheduled to return to active cargo duty as soon as she is sorted.
On another note, the DHL A300 lost all hydraulics and flight controls during that event and landed by using differential thrust alone. So I guess the stick-or-not-to-stick issue doesn't really apply here, but, you know, like, whatever... 