The only problem with that scenario, though, is that if Clark isn't mooning over Lana, is he still on Loeb Bridge to save Lex's life? Because I think we're supposed to think that's the proximate cause of his depression that day, and why he's dejectedly staring into the water. Of course, he may just be wallowing because he feels different, but I think his total awkwardness around Lana that day is supposed to be why he's moping around on the bridge.