As I sort of said in that other
thread.
Why do you care that it calls "update" or "insert". Surely you care about it doing whatever it is that represents an update or insert?
In other words, you care that it makes the relevant call to whatever your persistence framework is.
I'm really not a fan of testing what methods internal to a class are called by the initiating method in that class. That stuff is (in my experience) very prone to change. You'd be fixing unit tests every time you sneezed.
I know others don't necessarily agree, but I felt like having a grump about it...