Spaced Ranger said:

The next version (so goes my theory) was with the home-video releases. Lucas himself would remove the SEN-talking-to-children shots and re-order the THX-caught sequence. This would be Lucas' second re-edit [3rd version, 1983].

Yes, I've had those thoughts as well but at this point I really don't know what to believe. The thing that would make most sense is of course that they simply used an '78 Interpositive for the home video debut. But with Lucas everything is possible I guess. We need to get ahold of a '78 release print.

I checked these editing points in the Italian TV version again and found something interesting...

Home Video version: from the medical examinations scene there's a dissolve to a corridor shot where he's taken away by a cop and from there it fades to black and THX is being monitored & researched.

Italian TV broadcast: from the medical examinations scene there's actually an awkward cut (part of the dissolve is still there!) to the same corridor shot where he's taken away and from there it cuts to trial.

A real botch job, that cut and the remains of that dissolve does at least tell us that this isn't the original editing. So why even make a cut here instead of keeping it as is? Obviously there must have been another scene before the corridor shot which the dissolve was used for. Will be interesting to see if it is exactly the same way in the 16mm print. It just keeps getting weirder...