The lawyer didn’t go into the statistical details, because that’s not his job or area of expertise. He did state, very clearly, that comparison of vehicles within the 5 star safety rating is not allowed, and that is explained in detail in their Guidelines for Communication. This is also the second time they’ve done this, and have been called out on it.
ETA: This is what the Advertising and Communication Guidelines document says about competitive comparisons:
Competitive Comparisons
Advertisements that competitively compare frontal crash star ratings or the Overall Vehicle Score of two or more vehicles should occur only if the vehicles being compared are within 250 pounds of each other and within the same vehicle class. Comparisons for frontal crash ratings or the Overall Vehicle
Score should not be implied between vehicles where the difference in weight exceeds 250 pounds or the vehicles are of different body styles (e.g., comparisons between a sedan and an SUV, even if of similar mass).
