Google Maps uses, among others, images from the Ikonos satellite. Here are the specs:
It has a panchromatic sensor (greyscale) and red, green and blue sensors. Ikonos has a ground speed of 6.8 km per second, so even if the sensors are only a few centimeters apart, the images would need to be recombined at an offset. The offset would be tuned for static ground objects.
So I guess the ghosting is due to both the altitude and the speed of the airplane relative to the ground.
EDIT: here's another plane with the same (grey, red, green, blue) sequence: http://maps.google.com/maps?oe=utf-8&ie=UTF8&gl=us...
The sideways offset seems to be roughly half as much as the offset in the direction of movement of the plane, so at least that component would be due to the sensor platform moving...
It's also not the sensor distance that contributes to the halo effect for some satellites, it's the capture time. Often, each band is captured one after the other. Some satellites, like Rapideye's, have several seconds between certain bands. For instance their B/R bands are (I believe) first/last bands captured (of 5 total), so all moving clouds in their imagery get a red/blue halo.
What are the chances of that?
PI * 0.5 * (0.5 (square miles)) = 2.03417191 square km. let say 2. That's the size of the disc around the plane where your house could be.
10000000 * 0.01 * 2 = 200000 That's the total number of those discs fitting in densely populated US.
So 1 chance out of 200000, that's in the same ballpark of the size of HN community, so it was likely to happen to someone, but it had to be YOU ;)
I didn't use exact numbers because I have no idea what numbers you have to use to convince yourself that the number of hacker-location pairs would scale quadratically with the number of hackers, as in the birthday paradox. It makes absolutely no sense.