I think whoever wrote that article is FOS. They stated that the "test" rifle was a "short action 308", yet you can clearly see that the bolt is longer than the other 2 short action examples pictured, and so is the ejection port. The cutout in the stock, however, appears to be the same length.
My guess is that the magazine box is 2 different lengths for long and short action(with the short action model utilizing a block for smaller cartridges like 223), but that the action itself truly only comes in one size. Long. Meaning a short action edge would still have the same bolt throw/ejection port as a long action model, i.e., longer/larger than the Savage and Stevens pictured alongside it........