So, the Creeth ambassador is carrying a bomb?
No. He is a bomb.
His protein-chain fuse will set him off during the negotiations, likely killing everyone there.
And we'll have the Golbwerian military after us in no time.
If we don't deliver him, though, the Creethlings won't pay us, and will probably send their military after us.
As long as we are going to end up running from a planetary fleet anyway, we might as well get paid.
As long as we are gonna get killed, we might as well keep him on board and watch the fireworks...