I have only seen the Japanese version. I think the only time I came across the English dub was when watching Amanda’s audio commentary track.
Ritsuko’s Japanese VA sounded defeated as soon as Casper betrayed her, and the animation does a stellar job visually expressing the defeat as well. If being betrayed by your own mother’s handiwork isn’t enough for you to believe that Ritsuko should start feeling defeated at that point, then everything after that exact moment could be attributed to Gendo pulling out his own gun, which, I think you’ll agree, is a pretty big moment of defeat for Ritsuko in and of itself.
I’m not sure what you guys have against all of the visual/audio elements of this scene being complete in their own right, thus being ripe and ready for interpretations based on their own merits. Like I said, this isn’t rocket science; it’s basic film language. POV shots aren’t that much more complex than a a set of shot-reverse-shots, so this really isn’t any stretched logic here. I mean, I get how it can feel anti-climactic to have all of Eva’s “mysteries” boils down to Occam’s Razor, - the most likely conclusion giving the available information, - but that’s just how these things go sometimes. No need to assume complexity where none is needed. And I know it might be radical to apply simple film language theory in a forum that is more interested in exploring Evangelion’s vast world-building than it is in appreciating the art for what it presents itself to be, but I think that there can be room for both.
But I can’t help as though I might have acted as the fun police, suggesting that because the silent line was meaningful in its own way that speculating on the silent line wasn’t a meaningful endeavor, and I didn’t mean to suggest that. It’s fun and can serve somewhat as a Rorschach test for how we see Gendo as a character. If you ask me point blank what he said there, my guess is that it’s “I need you/I needed you,” or something like that, given the context of how the rest of the movie plays out, and the fact that Gendo is never shown to be vocal about his capabilities as a pimp-daddy, as OP suggested. But as for why the line is rendered silent in this movie, well, like I said, it’s evident in the language the film uses in that scene. As all of you have already exquisitely point out, the line was going to be silent from the very beginning, as evidenced by the earlier script drafts of the film. I just find it interesting that, out of all of the methods the filmmakers clearly explored to mask the line (off-screen explosions, etc.) the filmmakers decided to switch to Ritsuko’s POV shot at that time to provide an emotional reason for the silent line. You can’t argue that all of this isn’t evident in the film. (Which is probably why you guys have been exploring reasons outside of the film in order to figure out why I have this theory, like asking if I’m psychopathic or if I’ve only seen one of the two existing English dubs or whatever.) It’s all there in the Japanese version of the film itself. I’ve presented my case clearly and I've cited my sources and reasonings for doing so. There is meaning in the silence. I don’t think we’re meant as the audience members to go seeking out new meaning to that (or any) scene in Eva that isn’t already contextually self-evident. It’s fun to guess what the line could have been, but were not expected to, and thereby it isn’t necessary to understand the meaning of the scene itself.
TLDR: Why you booing me? I’m right. (Or, at least I’m right as anyone can be when it comes to this scene.)