I also saw that video and it made me wonder about Chris (Mansfield/Sante)'s claim (AGH, too many Chrises... I'll just go with Sante and Ayra).
What Ayra says there in the video doesn't necessarily rule out that he killscreened, just that he's going for a big score. It's up to interpretation.
I'm trying to remember exactly what Sante told me, but supposedly the word came from Billy himself that Ayra did it.
I then asked Sante how Billy could have possibly said (in KoK) "gee, I don't think anybody has" when asked who else had been to the end if he was personal friends with somebody who did, but he basically said (and I agree) that you really never know with Billy, especially when there's a camera in front of him.