Bug report of Kill off civ assimilation bug:

It's turn 46 and I'm just about ready to kill off the Sophons. I purposely didn't assimilate Arcturus just to show this kill off civ assimilate minor civ bug. Currently I'm at 92 diplomatic relation with Arcturus and gaining +1/turn. Their ally is the Sophons.
Proceed with the ground invasion of Spica killing off the Sophons. Once they are killed off the game will assimilate Arcturus to the Sophons thus keeping them in the game. If the Sophons had enough influence to assimilate them before being killed off why didn't they? This seems like they didn't
have enough influence to assimilate and there is a bug in giving it to them once killed off.
If I was the ally of Arcturus then the Sophons wouid have died off like they should have.