That's the problem with deinterlacing using eedi2. Here's a better version (well I think it's better):
http://www.screenshotcomparison.com/comparison/122076
It's still degrained, but this time I left the residual grain in. No distortion on Vader's chest-plate this time.
And by proper upscale I mean a more complete upscale. You wouldn't use just spline64resize to upscale video to HD.