If not for those meddeling patriots alerting a cop that there was a shooter on that roof and that cop alerting that sniper and that sniper blowing yearicks brains out Yearick would have been snuck out of there and Crooks would have been swatted within hours.
Think that over and put the puzzle pieces together.
The patsy swap would have worked if Yearick could have got back down that ladder and hidden by those who got him there. Later on, when he's long gone, the fblie would go get Crooks.
There's as much proof that Yearick was there as much as Crooks was there.