Fallout 3 tempenny tower macre quest?

i saw a video on youtube this guy went underground of tempenny tower and released someone i cant see then he went upstairs to the main entrance of tempenny tower and there was roy philips, they went inside and start killing the people and after that he turned into a ghoul, i want to do the quest but when i first came to tempenny roy philips was on the speaker and i thought he would stay there talking forever so i killed him, would i still be able to do the quest?