NHL Rejects Ilya Kovalchuk – New Jersey Devils Deal

TSN: The NHL has rejected the contract between the New Jersey Devils and Ilya Kovalchuk as “it circumvents the NHL’s salary cap.”

I understand why the NHL did this, but I don’t understand how they can do after letting so many deals that “circumvent the NHL’s salary cap”. From my understanding, Lou followed the ‘rules’ of the CBA, so what grounds are there to reject it? I look forward to reading the NHL’s explanation.