However, localised areas could be weakened by external damage and then fail under pressurisation loads, could they not?
This could give rise to destructive decompression.
Explosive decompression is a nice, convenient plot device in the movies to add tension and remove the odd Bond villain or two, but unless you have a major area of the fuselage break away like it did for the Aloha 737 (IIRC) over Hawaii, it is not going to happen.
Good Old Mythbusters had a try at shooting out a window and puncturing a pressurised fuselage of an aircraft by gunfire in the hope of proving explosive decompression was an actual phenomenon. Needless to say as there is only a few psi difference in pressure between inside and out, there isn't enough force to drive crack propogation in either a window or more importantly, the fuselage skin. So explosive decompression was judged as "busted".
If it came to the crunch that a crack created by impact with ground equipment was big enough to have a large enough force applied across it by means of the pressure difference, then the crack would certainly be big enough to be obvious.
The CFRP in a 787 is also probably a damn sight more reistant to cracking than the aluminium in a conventional aircraft. I understand from industry publications that much of the skin panels in the 787 are composed of three dimensional woven fabric, rather than uni-directional roving. Hence the finished panels have fibres running perpendicular to each edge and surface which significantly enhances its resistance to transverse cutting or cracking, whereas the metallic skin, despite years of metalurgical research into microalloying to avoid cracking can still in unfortunate circumstances prove to be susceptible to fatigue and stress corrosion cracking in any direction.