Red Color Shift
Seems logical to me that a camera, upon seeing an intensely red object, would suspect that some of that color was due to the light source, and hence try to remove the red "color cast" it perceived as coming from the light. That's what AWB does, really - it looks at a scene and tries to guess the color of the light, and then correct for that. When shooting things with really strong colors, it is probably better to select a specific WB setting (or use manual) to make sure the AWB isn't fooled into thinking the color of the object is due to the color of the light and therefore trying to tone it down.
I was able to adjust using hue controls in Aperture, but I
shouldn't have to do that under normal daylight and auto white
balance (although adjusting white balance in post did not correct the
problem - i tried just to see).
Does Aperture give you independent temperature & tint controls? If so, it sure seems it should have been possible to correct this, at least to some extent.