There is no such duty since this is not a case nor a trail, this is "preliminary investigation", which is something that a prosecutor in Sweden does in order to determine whether there are grounds for actually bringing a case to trail or not. And the reason for there being no speedy trial is of course due to Assange hiding in the Ecuadorian embassy.
There have not been a long row of prosecutors involved, senior or not, in this case. The initial case where lowered from rape to sexual molestation by Eva Finné who is an ordinary prosecutor. Marianne Ny who is the one who raised the allegations from molestation back to rape is the senior one since she is a "överåklagare" (higher prosecutor). It's true though that she received criticism from the Court of Appeal that she had not done enough to speed things up, which is far from "acknowledge that her tactics considered of delay after delay".
No it's not muddled, if you have legal presence in a place you have to comply with the laws of the place. The reason Uber manages to dodge some of the bullets fired at them is because they have no legal presence in the place, it's the drivers that do and thus they are the ones getting into trouble. Both Apple and Google want to have physical and thus legal presence in Russia so there is no Uber-like situation here.
And judging by how things went for Kim DotCom, TPB and so forth, Uber might soon find themselves into uncomfortable conditions. Apparently they where involved in over 173 lawsuits just in 2015, that number have probably increased over the last year.
The removal of the LinkedIn app from Apples App Store and Google's Play shows the willingness of major internet gatekeepers to comply with individual nations' data-control laws, on both the web and mobile devices.
Since exactly when have any company on earth managed to ignore the existing laws in countries where they operate?
For every bloke who makes his mark, there's half a dozen waiting to rub it out. -- Andy Capp