Oh yeah the whole intel/demo thing is a complete farce. No way that is a demo. I have seen a few intel demo's and they are usually just empty boxes. or plastic chips presented.
I would bet this was done before the shipment hit the US. The boxes were most likely the same exact weight as the originals and this would fool 99% of the shipping chain as it is almost all automatic. Even the Newegg warehouse is almost all automatic until final packaging, everything there is done by weight.
Far as I know, the only time people at newegg put their hands on a product is when the order bin stops in front of the shelf and a light blinks. After that the next time it gets touched is when it is boxed for shipping. I would bet that neither person involved knows anything about detecting counterfeits or QC and probably doesnt care.
As for what newegg has said about this, that story was carefully calculated by PR and lawyers so as to not cause any issues.