Questions & Answers about Han snakker som om han visste svaret.
Why is the past tense visste used when this is about the present?
Does the sentence imply that he actually doesn’t know the answer?
Usually yes. Using visste gives a counterfactual flavor: he talks that way, but he likely doesn’t know. Context can soften this, but that’s the default reading.
Can I say Han snakker som om han vet svaret?
Yes, but it changes the implication. With vet (present), you tend to suggest that he actually does know. Many speakers still prefer visste; use vet when you want to avoid the counterfactual nuance.