Which claim? That the shot of R2 doing something before R5's motivator blew out was there, or that it was later cut? Because I definitely remember seeing it.
That any footage of R2 doing anything to R5 was filmed.
Like I said, I saw it. It was ambiguous, but that was definitely the impression -- that R2 sent a signal of some sort that overloaded R5's motivator. That's been my interpretation of that scene for three decades now, since well before the movie got recut or retitled or modified to the extent it's been today.
Besides, doesn't it make sense? We know that R2 was on a mission. He had to find Obi-Wan, and being stuck on a Jawa sandcrawler wasn't where he needed to be. Throughout the whole first act of the movie, he was doing whatever he needed to do to deliver Leia's message, by hook or by crook. He stole the escape pod to get down to Tatooine, and once in the Lars' possession, he tricked Luke into removing his restraining bolt and then wandered off to find Obi-Wan. So I don't understand why you'd even be skeptical of the idea that he deliberately made sure that he was the astromech droid that got purchased instead of R5. Surely that's more consistent and less coincidental than R5 just conveniently happening to break down at exactly the time R2 needed him to break down.
The sad thing is, that sounds exactly like something that might have come from an EU novel....
