Some key points that are a bit hard to grasp, at least in some versions:
- How did Bill Haydon know Jim Prideaux was going to Prague if it appears to be organized as a closely guarded secret by Control?so which one is it?
- the film suggests Prideaux must have told Haydon himself, his close friend, against Control's orders of secrecy, out of loyalty, and in order to protect his friend.
- The series suggests it was a honeypot
- How does Smiley deduce that the Witchcraft source, Merlin, is Poliakov? A key step is when top people at the Circus question him about Ricki Tarr, and appear to suggest that there is a link between Ricki Tarr and Merlin. And Ricki told Smiley that Poliakov as the link to the Mole. Smiley understands that it was Karla who tipped off London Center about Ricki's coming through Merlin. He also observers that Witchcraft gives ideological infiltration campaign intelligence after Ricki comes back, as a way to discredit Ricki. It is still all a bit indirect.