Anyway, here’s a good link that ‘explained’ it all back then. I didn’t see this at the time, but I note from the comments below that someone did spot this anomaly in C3PO’s last moments. - io9.gizmodo.com/so-now-we-know-how-c-3po-got-his-red-arm-in-the-force-a-1770741572
Here’s a better link and a nice bedtime story by the man himself: http://www.youtube.com/watch?v=qOuF2yh1lKU&t=47m15s
Sorry about the off topic, I just enjoyed his reading even though the story itself is a bit mushy.