The others at the temple, treat Sayid's wounds with the fountain of youth. The waters are tainted, at this point they do not know Jacob is dead, unless he has died before in their life times. They do however somehow know that there might be something wrong with Sayid if they heal him with the waters. This is the same thing that was said by Richard concerning young Ben long before Jacob "died". Richard took young Ben who was coincidentally shot by Sayid in 1970's Darmaville, into the temple in order to save him. Richard presumably takes Ben to the fountain of youth to heal his wounds, warning that Ben would be "different" afterwards.
Ben was a young boy, who is resented by his father because of Ben's mother's death in child birth. He isn't "evil" until after being saved in the fountain of youth. Keep this in mind...
Rosseau's crew, enter the temple via smokie and are some how changed. We don't know for certain whether smokie changed them, judged them and released them... or if the fountain's waters somehow changed them. I'm leaning towards the waters being the culprit of their insanity.
Smokie however, didn't kill Ben when Ben was "judged" because Ben genuinely said he was sorry, or possibly because Smokie was manipulating him all along, this remains to be seen. Smokie did outright kill Mr. Eko who denied regret during his judgement for his actions that caused his brother's death, etc. Smokie kills Widmore's agents, and Jacob's agents without passing judgement, as far as we can tell.
Now here is my theory... the others at the temple, along with Richard, have some advanced knowledge of the waters healing powers. They also know that these powers have consequences, but they also allow the healing of Sayid... only to then watch him like a hawk for signs of wrongness.
My theory is that the candidates, the true candidate rather, gains the immortality that Richard has without the insanity side effects. Perhaps they heal Sayid only to see if he is "the one" to replace Jacob. If my theory is true... I'm guessing Claire has gone insane not by the hands of Smokie, but by the waters of the temple, as she is a rejected candidate like Ben, or possibly Sayid. Obviously it remains to be seen if Sayid will go crazy, or become the one, or whatever. Either Smokie is evil and wants to kill the candidates once and for all ending the game, or he is good and wants to simply leave as he told Sawyer.
I am still in the camp that the smoke monster, is not evil, and that Jacob is the manipulator, the tempter, the puppet master.