We're talking about Buddy, not Tony Montana.Like I said, chances are pretty likely he knows the police are coming because he's listening to police radio using a scanner. I don't know how easy they are to get in the US when you're a criminal, but in Europe they are pretty common to buy for everyone.
The guy operates out of a shithole for drug addicts, he looks like a drug addict himself, there's no way he has the resources to get out of this or do anything from prison.
As for the police raid, it's not an emergency operation where they arrive with all their sirens blaring, and the dispatcher calls all the units in the area. It's an operation mounted following a tip-off, so a discreet intervention.
Buddy is definitely out of the equation, in jail or worse if he had the bad idea of resisting arrest. That leaves only Vinny for one last face-off.