Yeah - but when Steven told Webb he was in Vegas but could get back there if needed, Webb told him no - he was already en route and he would cover it. I'm thinking that if he realized somewhere along the way that he COULDN'T get there in time, he would have given the Bishop a heads up - AND mentioned that Steven couldn't be there either. That obviously didn't happen - hence Seth's call to Steven at 11:15 AM.
I know...I was just avoiding the dreaded "repeat it all back to you"

The part I don't understand is why (after Steven told Abboud he couldn't be there), Abboud dials Steven (at the direction of the Bishop) to find out if Steven could come. Maybe they were just trying to figure out if Steven had come back. Of three who alternate, two are in Vegas.
The problem's probably simple: conversations took place that weren't that important EXCEPT for the issues at hand; no mental archiving for investigative purposes.