Or perhaps the GMs should have known that CBAs don't last forever and started immediately circumventing the Salary Cap that required a lockout to implement.
And perhaps, they should have thought that 13 years contract that runs through the players 42nd birthday is a bad idea regardless of the rules, eh?
They did worry about the risk. Any article at all says "Hey, this is a great deal because of X, but it is kinda risky to sign any player for that long." Even ones written by the team for their website.
The risk is just mitigated for a guy like Zetterberg who you know is an everydayer of everydayers.
And everyone here who is talking about "oh, you violated the spirit of the rules" needs to wake up and join the real world. Whenever you deal with a finite set of resources (as a cap world makes you), you look for any legal advantage you can. You can say "Oh, they meant to circumvent the cap by these deals", but why didn't the league take that into account when they made the cap? I mean, it's not rocket science to come up with "AAV is $/# of years, so if we bump up the number of years, the cap number comes down." Sports are a business, clear as day, and in business, you take every advantage that you can happen upon.
The NHL lazily negotiated in the 2005 lockout after they landed the salary cap and left it wide open for something like that to happen.
It is their responsibility to enforce the rules. If they chose not to (which when they approved all of those deals), the rule is not being violated.
It's not up to the GMs to know what the league might deem worthy of punishment four or more years down the line. They can limit their usage of a loophole to their most vital players and/or not utilize it if a CBA negotiation is coming, but if there is a legal loophole, they are stupid to not use it. Them retroactively applying a rule to contracts that were previously ruled valid as written is not common and should not have been a thought in a GM's mind, especially in 2009.
Even so though, I don't know why this is such a thing. There is no way that the league comes down on Detroit when they've let Pronger do what he's done, Hossa has magically become allergic to his pads as soon as he starts making $1M, and so on and so forth. All sports leagues and whatever will always shy away from destroying/materially affecting a team even if the rules say they should.