The NHL doesn't have to do it. It has the discretion to do it. Just like it had the discretion to void the Hossa deal. The fact that it did not void other deals not make Kovi's deal kosher. NJ took a chance that the NHL wouldn't exercise its discretion under the CBA, and it did. There is nothing inconsistent about the same Kings fans arguing for extending an offer to Kovi which would have triggered the NHL's ire and caused it to void the deal. It was a risk because the rule is a big, untested gray area.
Ok, you need to look a little bit deeper than that. Look at the annual salary by year.
For example, you might hear people say Luongo's contract is circumventing the cap. However, I think his contract ends with a $3.5, 1.5M,1M,1M for the last 4 years. Now, compare that to Kovy's last 6 years of 750K, 550,550,550,550,550.
See a difference?
Hammond:
Dean Lombardi said tonight that the Kings would remain interested in signing Kovalchuk should the opportunity present itself, but it’s likely that the union will get involved and seek to uphold the deal.