CatBus said:

Well, there is a way to reconcile those things. The whole point of blowing up planets was for people to know about it ("Fear will keep the local systems in line"), so obviously they're not going to cover that up. On the other hand, while there was no way to prevent people from getting the idea that they were looking for droids (asking "How long have you had those droids?" to everyone passing by), they may have wanted to cover up the fact that they were so completely desperate to find them, lest someone say "Hey! Maybe these droids they're looking for have something valuable I can sell to the rebels." So it's not that they're trying to cover up who the true perpetrator is, they're just trying to cover up the perpetrator's motives, and this was an easy way. But they didn't count on the mystery-solving aptitude of Magruff the Crime Jedi!

Yeah, it's not the best explanation, but it's not the worst plot-hole either. I give it a pass.

That is the assumption I've always made. Never even gave it a second thought. I don't even think it's a plot hole.