DB Multiverse

You've seen on page 430 that we believe Freeza chose to destroy the Saiyans without a need for a particular offence. This is the same as in the TV special.
In Dragon Ball Z episode 78, there is a flash back scene with King Vegeta attacking Freeza. The latter says that this attack was the reason for the planet's destruction (Toei likes to contradict itself).
Also in the manga, Freeza says that he killed King Vegeta himself (volume 25, just before he transforms).

So we made a scene taking the best of all :
— Freeza decide to destroy the planet, then go to it.
— First, King Vegeta comes on his ship, and talks to him very harshly. He is killed.
— Then, Freeza takes the army out, Baddack show off a little, and the army and planet are destroyed by Freeza.