*** Yes, he did flee. The claim that Assange was "free to go" as promulgated by Björn Hurtig, a former attorney of Assange's. He tried that same line in court and got smacked down by the judge for trying to deceive the court, and then got an official reprimand from the Swedish Bar Association.
I can't confirm or deny your claim here, but the link you provide doesn't confirm it either:
Riddle was referring to testimony in which Hurtig had said he had been unable to contact Assange last year when he was sought by Swedish prosecutors for questioning.
Nothing is said about whether Assange was free to leave Sweden or not, but a court order banning you from leaving the country usually means you hand over your passport. Since the UK is not part of the Schengen Area, he would have needed a passport to enter the UK from Sweden.