Interesting Question: Human Eyeball Inverse Telecine?
 

Does the eye or brain inverse telecine progressive 24P film in realtime when watching something in a theatre? Just wondering, when I thought I saw Inverse Telecined fields on the big screen!

When a progressive source is shifted to interlaced, if the fields were inverted in their display sequence, this would probably cause some flickering or jitter in the image, especially with moving subjects. Is this what you saw? The eye and the brain do some complex processing and sometimes trick you into perceiving things that are different than what actually exists.