To me, Briere somehow sold low on his players while not going towards any particular direction.
Flyers made cap space, for whom exactly? If they're saving room for future signings, they'll blow through the savings very quickly. Cap rising = UFAs ask for more. But value is created for existing contracts, which is what they traded away. Even if Farabee was having a down season, it's very unlikely Briere would be able to sign a better forward for that money July 1st.
Yet the return was mediocre futures. There's the 2nd rounder, which will probably be in the 50 range. Kuz has no value and will probably go back to Russia next season. Pelletier still projects OK but he's only a year younger than Farabee and it's up in the air whether he'll ever play as many NHL games, let alone have some seasons as good as Farabee's.
Without a follow-up trade the Flyers cleared some cap space and acquired a few futures, but they're straight up worse and the room they made isn't going to either get them back in playoff contention or help a potential rebuild. While the Flames got to dump a pending UFA with little value and a prospect who the Flyers would feel good if he could ever play as good as Farabee. They took on salary but you're completely fine with betting on a return to form for Farabee, at which point his contract would be a solid net positive.