That was a really cool scene to make, having a real-life astronaut interact with Optimus Prime (Peter Cullen ranks it as his favourite scene of DOTM). Icing on the cake. On the other hand, it was overdone icing. What was the point of having a real-life astronaut appear to verify part of a fictional story? Is it implying that Aldrin's claims of a discovery on the moon were real? I might just be reading too much into it. If Aldrin wants to take part in a fun movie, no problem. Still, it felt kind of weird IMO.