They aren't interlaced, unless you have some kinda weird monitor.
Some clips does look interlaced in media players if the media player can't cope with the bitrate so it tries to interlace it to play it properly.
Don't worry about it, just to be on the safe side you can de-interlace the clip in Virtual Dub or use a AviSynth script.
avisource("C:\source.avi")
tdeint()
Drag'n drop the AviSynth script to VirtualDubMod and re-render it with Huffyuv or a lossless codec and see if you see any difference.
Did you do a PB2Krail2BBGrind in that clip btw...?