The lesson from that scene is extremely powerful when you understand the same lesson applies to ANY problem. When you are faced with a heavily secured door, or an encryption standard, the attack vector is often going to be something other than going through the face of the door or the front end of the encryption. What you'd do is KICK IN THE DOOR. And the TLAs know this and do exactly that. Their people have always kicked in doors while normal people look at the locks and shrug and walk away.
In this case the lock has performed its function: it prevented Redford from effecting a clandestine break-in. It is now obvious to the office owner when he returns that he has been burgled and he can take steps to minimize the damage that will result from it.
In the security business it is accepted that ultimately you cannot prevent a determined attacker from gaining access to a physical location. The best you can do is 1) delay him and 2) force him to leave evidence that he was there.