You're both right, so no need to get testy.
It's documented in Atkins' books, for example, that it is quite normal for cholesteral levels (especially the impressive but not terribly meaningful total cholesteral level) to rise in the initial stages of a low carb lifestyle, as your systems adjust to the considerable changes in energy sources and balances. It is also normal (for the majority or 'vast percentage') for them to fall again, on a classic bell curve over a period of 3 months or thereabouts... it will vary per the individual. There are some with "resistant hypercholesteremia" and yes, this does tend to run in families. It IS a small percentage, though, and it isn't usually determinable
without doubt until a period of time (such as 3 to 6 months) has passed, with reasonably strict adherence to NOT mixing carbohydrates and fats.
It is sensible (and documented/recommended in the Atkins' books, again) to have your cholesterals tested, to determine your ratios (HDL, and Triglycerides and LDL especially) and to see a physician before starting any weight loss plan or massive change in dietary regime or lifestyle. This is NOT unusual, ask any dietician.
There is a great deal of reliable information on the subject of resistant hypercholesteremia at the GO-Diet
http://www.go-diet.com website (Dr. Goldberg: physican, low carber & resistant hypercholesteremic) and a great deal of information about supplements for treating hypercholesteremia (if needed or if concerned) at the Atkins Center for Complementary Medicine
http://www.atkinscenter.org
Enjoy the exploration and the information, and stay destressed