Which leads to plot inconsistency #3032 in Star Wars in light of the prequel trilogy. (Although, this really is a plot inconsistency without pre-quels as well.:
So Darth Vader chases locates, chases, and captures the blockade runner in the opening of Star Wars; a brazen act against a diplomatic, civilian vessel. They trace the plans and (rightly) summarize that they were ejected during the fighting. These plans are the sole known weakness in the Empire's bid at perpetual rule. Vader's on the 5 yard line.....and he lateral's the ball?!? He sends "a detachment" down to retrieve the plans?!? He's right there! He doesn't go down to supervise it personally? He delegates it to the galaxy's worst investigative branch: the stormtroopers.
In light of the pre-quels: this is his home planet that he knows better than some random blaster jockey. So he gets all the way there and rather than going those last 5 yards, he hands it off and watches the troopers fumble the ball.
Now maybe Tarkin had jerked his chain and he had to get back to Death Star 1.0 pronto; or maybe he was suffering too much mental anguish at the thought of visiting his mom's burial planet (though he seemed pretty cocky on screen). But I think it was just a plot convenience that makes little logical sense given the gravity of the stakes involved.