Plot hole: When we see Sentinel Prime being extracted from the Ark by Optimus, we can see that Sentinel Prime already looks the same way as he does throughout the rest of the movie. The Ark crash landed in the 1960's, the Rosenbauer Panther Fire Truck didn't exist in the form we see Sentinel Prime transform into. All of the other Autobots came to Earth in their proto forms and adopted a disguise when they arrived [we see them scanning alternate modes - one Decepticon is shown doing likewise in this movie.]. Sentinel Prime already has his disguise when on the ark, which isn't possible.
GalahadFairlight
5th Jul 2011