It’s pretty blatant. The other guests are telling stories about times they got mugged. I think Corden felt left out of the conversation and this was the joke about being mugged that popped into his mind. Corden chimes in with Noel’s bit about deflecting an attacker by whispering. He even does a gesture that is very Noel. He didn’t deliver it particularly well and didn’t do the context to lead in, so it didn’t land and he had to repeat himself. It was very clearly Noel’s bit. He’s done it loads of times, including at events where Corden was performing. There is absolutely no way Corden hasn’t seen the routine.

That is exactly it, and I think you just hit on the solution! I tested it myself just now to be sure, and it checks out. So, for those currently trying to access Boosh Docs via the blog or other links: try accessing it through your own Drives, using the "Shared with Me" tab. That should do the trick!