Seems like a bug anyway. The Assassination attempt was amde but when I talekd to him after it he didn't ask me to help him or anything, just the same old dialogue.

Normally he engages you in conversation automatically....
Try restoring a save from prior to entering Junktown...

Don't have one from before anymore. I went in a while ago and saw people trying to kill him, Combat engaged when was outside all the way to the left, by the time I got to the door the bad guys where dead and Killian didn't say a thing. I just recently went back to try to do somthing.

Do you have the latest patch?

No I didn't install it, then when I got the idea to I was already into the game, I installed it only to find out that i would have to make a new save. Is there anyway to convert the save?

IIRC you have to help him fight off the assassin to get the quest?

Unfortunately, no.

I think there is an alternative way into the quest. You can just go up to Gizmo before the assasin is triggered and he should offer you the assasin's job (wack Killian). I think you can then tell Killian, and he should then give you the bug and tape.

^^
Yes.... I believe engagin Gizmo in conversation should bring his distaste for Killian up.... This should allow you to offer to do the job for him, then you can rat him out to Killian...

That being said... I recently discovered a combat free way of disposing of Killian using gear obtained early in the game....

And your going to keep it to yourself? Damn you! <_<

Okay...

When visiting Killian, and performing a few save and load experiments, I was able to utilize the TNT you can pick up in... um... Vault 15?.... anyhow... I REVERSE PICKPOCKET the TNT onto Killian (after recieving the quest from Gizmo to collect his dogtags).... i set the explosive to 1 min... left the building.... Walking around to the rear of the store you can now see inside.... Wait a few minutes and enjoy the POP animation as Killian is atomically reorganized.... None of his guards react, infact I can go back in and talk to them, clear out crates and the safe in his room.... Definitely save before trying this though: the first time I attempted it the dogtags were vaporized and I couldn't finish the quest..... Every other time it HAS worked (other than the premature detonations that occasionally happen). Enjoy.