People have speculated that the culprit could have been a binary asteroid along with the Chicxulub impactor. Even if that wasn't the case, it's estimated that similarly-sized (~450 m) impacts occur every 50,000-100,000 years. That would mean there could have been many hundreds of such impacts in the 66 million years since Chicxulub, so not nearly as unlikely of a coincidence as it seems from reading the article -- especially considering the million-year margin of uncertainty in dating this smaller crater.