Freo did not gain an advantage by losing to Hawthorn. The players and coaching staff involved in that game from Freo were still trying to win the match. They just rested a lot of players to give themselves a greater chance of winning the following match. Freo would have been ecstatic to win that game in Tassie as it would have secured them a home final. Same thing happens all the time in the EPL, it is not tanking, it is smart list management.
What Melbourne did (allegedly) was actively try to lose a game. Huge difference and anyone that cant see the difference must be walking around with thier head firmly up thier arse, or so biased its not worth even discussing the topic with them.