Ah, yes. The de-briefing with the head villain. The absolute classic: verify that there are no leaks, and the only one who knows what happened is yourself. With no insurance to keep you alive.

"Health and safety incident". So Bria's attempt to make it look like a workplace accident was officially successful.

You know, if Vader keeps killing everyone, soon she won't have anyone left. This is before Episode IV, so we haven't reached the point of getting a warning choke first. Bye-bye Krennic.

Now, let's talk about the concept of plugging the leaks. First, every clone trooper who saw the scientist murdered will have to be killed. No problem, they're clones.

Next, all the normal troopers who fired the guns will have to be killed. These people are likely to have family; people who will notice that they are missing.

(I'm reminded of the Flintstones spoof where Barney accidentally kills Fred, tries to hide what happened, realizes that every kitchen appliance is a living, talking creature that will squeal, winds up trying to kill all of them, and things just keep escalating from there. (Let's see DMM manage to find a link to that. Have I finally managed to stump him?))

Normally, this would present a problem. If you keep having workers disappear and die, no matter how big and powerful your evil Empire is, people will not want to work for you. You'll wind up having to force your population to work for you, effectively enslaving your own people. That never works well; it's practically begging for a Rebellion to come along and free them.

But in this case? The Rebellion actually came in, shot up the place, and killed people. So anyone that the Empire wants to "disappear" just officially died in the rebel attack.

Don't blame the Empire, blame the Rebellion. You can even let the reporters in to examine the wreckage, they will clearly be able to tell that the place was shot by spaceships, and probably even tell that a LS fighter TIE fighter exploded from combat damage.

Of course, there will still be some naysayers who insist that the Empire shot up their own place to kill people. Conspiracy theorists like that are always a problem for any large empire. Just kill them.

— Keybounce