- They can interview him where he is now, and move things forward at least a little bit. - They can wait - possibly forever - to interview him, and not get justice for anyone.

What changes if they interview him now?

They claim there are legal issues with it, but this would not be the first time someone had been questioned on foreign soil, and it would not be the first time someone has been charged in absentia if they were to go down that route.

He won't magically gain superpowers and fly away from the Ecuadorian embassy if they charge him before they have him in custody. All that realistically changes is that they have to publicly make a decision whether to file charges or not.

So the question the is why is that a problem? The cynic in me tells me that the most likely reason is that they don't believe they have a strong case, and that his dogged insistence on not going to Sweden suits the prosecutor perfectly.