I read details on the site-that-must-not-be named that Grssiom and Nick process the alley/crime scene and discover McKean is lying because he claimed he heard the gunshots. But Gris remembers there was loud music playing from a nearby club at the time, making it impossible for MCKean to hear gunfire.
I saw that too. And, as stated before and shown in one of the videos, Nick finds prints when he rolls the passenger window up on Warrick's car. Whether they are usable, who knows?
In the Parade magazine last weekend, someone wrote in and asked about WP leaving, and in the answer about Fishburn coming in they said he was going to take Grissom's place in charge of the lab.
So which spoilers are right? He's the leader or he's a CSI Level 1 and Catherine is supervisor? If he's really a Level 1 then why would such an acclaimed actor take a "non-starring" role?
My thought is that with this strange gene he has and all, he may just be joining to fill out the rest of the season after WP leaves and then he will go out with a bang. This gives them the opportunity to write another big storyline where they can feel free to turn one of the CSIs into a killer or just plain kill them, and also gives them time to figure out what they really want to do as far as replacing WP for next season.