Important point of consideration is that GMK requires vendors to indemnify them (i.e.: cover GMK's legal costs) in the event a 3rd party makes a IP claim against GMK.
In other words, even if Nike takes GMK to court and loses, Cannon and the other vendors still need to foot GMK's legal fees.
That's why if a kit even sniffs of IP infringement, no vendor in their right mind would touch the kit with a 10 foot pole.
So, talking back and forth about whether or not something is IP infringement is a red herring. The real talking point is you don't want to go around shining a spotlight on yourself for something that even has a hint of IP infringement because if GMK gets taken to court, then the vendors are completely screwed as they can't afford it.