You are right, I didn't remember the first interview. He was, though, subsequently told he was free to leave, after the first prosecutor decided there was no case. When he's a new prosecutor well known for her aggressive activism in expanding the scope of rape law then decides to override, there's every reason to be worried, whatever you've done or not done.
For being "well-known for her aggressive activism in expanding the scope of rape law" it's surprising I can't find anything about it on the first 3 pages of Google that pre-dates the Assange trial.