Wait, aren't Nicky Skins' tapes inadmissible as he isn't there to corroborate?!

I have a question… I thought mob guys weren't (supposed) to take guilty pleas? Doesn't taking a guilty plea equate to admitting that "this thing" exists?

And… I think it's fair to say "Bent Finger" Lou gets the award for biggest pussy… ever. Why the hell did he turn over a year or two's sentence??