It's the fact that poor pick and roll defense (always hedging) leads to bad rotations, easier penetration which both lead to one three point shots because players can't recover quickly enough, especially guys like Caron Butler who isn't some speedy Eric Bledose guy who cow cover so much ground.
Clippers played a trapping defense, it meant a lot of recovering. So when Blake hedges out onto the ball handler, the ball handler's general main option is to pass to the screener who is rolling or popping and when you have to help in the screener, he gets open options because the second help is now the player hedging.
New York has an interesting defensive strategy for this where on a hedge they send I believe the ball handler's defender straight to the corner so when the corner man is helping on the rolling/popping screener, his man isn't left open.
Scenario: Opposing PF sets screen, Blake hedges. Screener rolls to the middle, ball handler gets him the ball, DJ rotates to help, screener reads it and passes to the man DJ was guarding, DJ's man gets a layup. Let's say instead of DJ's man being open, Butler comes from the corner and helps, screener passes to corner shooter, open / slightly contested shot, usually going in.
If Butler comes off the corner to help, screener passes to corner shooter but Green covers Butler and gets there, corner shooter makes one more pass to Green's man, Paul tries to help, but he's too late, again, basically an open shot, but you see how many help situations you now have. To have good 3PT defense with this system, help needs help and again needs help, and you also set up mismatches,
It's the whole team, it's also a system issue. Scrambling defense requires very quick recoveries, great communication and a whole lot of trust that people have your back. It's weakness is quick ball movement and giving up three's..
I YouTube Clippers defense and this was actually the perfect video of what I'm getting at
It's hard to imagine this being as much of an issue with Doc though: