[mroll]

I have also heard that, but only from secondary sources. Here is a clip of Russell talking about the time he wrote the first lisp interpreter. He doesn't mention McCarthy being surprised, but he seems to imply that he, Russell, was quicker to grasp the idea of translating the functions McCarthy had been writing to machine code.

http://www.computerhistory.org/pdp-1/1020b307d766e0019de2b4a...