[yborg]

To me the most remarkable thing about this story is that the KGB was apparently stymied for an extended period by the fact that Filatov had a "difficult" lock of "foreign origin" on his apartment door, to the extent that they had to steal and copy a key carried by his wife using an elaborate setup. It seems odd that an agency known for its skilled spycraft apparently was unable to pick a door lock.

[sciurus]

I'd guess the problem is if you spend a long time trying to pick a lock in an apartment building, it looks pretty suspicious.

[godelski]

Well if you watch videos like Lockpicking Lawyer they make it seem like a skilled person can open a typical door in a few seconds. Though he's probably pretty experienced compared to even the average locksmith or spy.

[R0b0t1]

If you learn a lock you can open it quickly when pressed, but most pick-resistant locks are quite troublesome to open. If you can't bump the lock or use a pick gun and the area is not secluded it may not be reasonable to pick the lock.

[Tanath]

And I think that's the issue. It was a foreign lock they weren't familiar with so didn't have one to practice on. It was apparently easier to copy the key.