Apparently O'Neill's brother accidentally listed his height as 17 cm instead of 176 cm on a health form for his future employers, but filled out his weight correctly, giving him a BMI (body mass index) of 149,000 (the ideal BMI range is between 18.5-24.9). For some reason, the employers' first thought was not the logical conclusion of "mistake" (17 cm is 6.7 inches), but instead, "Sweet Jesus, this man has a BMI of 149,000!"
Anyway, these future employers were now very worried about him, because they thought he was a vastly overweight person (not as worried that he was shorter than a newborn baby). Despite him trying to reassure them that he'd simply made a mistake when writing down his height, they remained skeptical, and insisted he see a doctor. Which he did. And then he added a "6" to the end of his height. Problem solved.