I don't understand why people consider letting a FA walk some kind of horrible disaster. In some circumstances, it makes sense to use the player during his prime, get value from him, and walk away. This is especially true if you're a contender and that player helps you to the playoffs multiple times and you have a ready successor in place. I wouldn't make a habit of letting guys walk (try to at least get a comp pick when possible) but in some cases, it makes sense. Is Plouffe that guy? I don't know. That depends on Sano as much as it does Plouffe. Only time will tell.