I felt like kicking the author in the head when I saw that.
I use asserts all the time in code and eventually replace them all when I write more code. I use them when I haven't written the logic required and want to be alerted when I run into the code instead of writing an exception which will be deleted as the project gets closer to completion.
Exceptions also blend in with production code more easily which I dislike. An assert is easier to notice than throw new Exception("Some generic msg or 'pretend i am an assert'");