I'm very interested to get your thoughts on why bringing him back was so disastrous?
With that trade, the Leafs gave up a 1st round pick for a 29 year old but rapidly aging (injuries, playstyle, etc) Clark, and a 21 year old Kenny Jonsson for a 26 year old Mathieur Schneider. There were also a handful of inconsequential prospects involved. It was a short-sighted deal for a team that was headed in the wrong direction, and the first round pick turned into Roberto Luongo to add an element of embarrassment to the whole thing.
Ironically, Schneider, while older and less versatile, outlasted Jonsson in the NHL by 6 years, and the Leafs eventually turned him into Bryan McCabe, so that portion of the trade turned out pretty well for the Leafs. On the other hand, trading the 1st when their core was near the end of it's rope turned out about as badly as it possibly could have (the second of 3 times the Leafs did exactly that in less than 2 decades), and there's no excuse for that lack of planning whether you think they'd have picked Luongo or not.