The first time I saw Rab ne, I watched it without subtitles. Now, my hindi is not quite to the point where I can translate each scene line for line, so i was able to convince myself that Tanni must have recognised her husband (or at least the semblance) at some point before the climax. I (as well as the rest of the world) just happened to blink and miss it. Re-watching it with subtitles, I kept looking for that missing scene. Unable to find it, I decided to insert it myself.