Inverse Telecine File Size Grows - Should Shrink eh?

[Bikspk]

Why would applying an inverse telecine result in a larger file size given that compression (Huffyuv on Video, none on Audio) is the same?

Shouldn't the file size shrink by 20% since you are going from:
AA AB BC CC DD (5 frames) to AA BB CC DD (4 frames) ?

The video in question has no other filters applied.

[gameplaya15143]

yuv vs. rgb compression with huffyuv. Unless you told huffyuv to convert it to yuv, then it is using rgb unless you switch to fast recompress, and the result will be bigger.

(note: is it yuv or yuy2.. I can't remember, I don't use huffyuv on a regular basis)