The inaccuracies that Dr. Davis and others discuss in the LDL calculation affect those with very high or very low TG. That applies to Xuan (her LDL is probably lower than calculated given her very low TG) and with her awesome freakazoid HDL she probably should have no worries.
Jay's numbers are a different story: the HDL is nicely high but not crazy high, the TG is low average and and not likely to throw off the calculation, and the LDL is off the charts. It might be nice in his case to get a sense of the ApoB/ApoA ratio and the true LDL particle count.
Plugging Jay's numbers into the alternative "Iranian" model for LDL calculation doesn't change the numbers much. Plugging Xuan's numbers into that model drops her LDL from 139 to 107 (that is, from elevated to normal). I'd bet in her case that reflects something much closer to the truth if she had a true LDL particle count done, and I'd bet that her ApoB/ApoA ratio would be very favorable.
Not a doctor, not giving medical advice, check everything you read here with a real medical professional, etc etc.