Bernard: Silence (he doesn't know the answer) Albert: Silence (he doesn't either) Bernard: I know it!
Basically it's nonsense.
If we can deduce the answer from silence then there's no need for any of the information given in the question, it's not a logic puzzle it's bullshit.
I don't assume Albert and Bernard are anything, if you've made assumptions beyond what's stated in the question then you've done it wrong.
And yes, I understand timing oracles.