He's making a fair point, which is that certain types of classification methods basically involve "fitting" a hyperplane to a dataset in such a way that the hyperplane divides the data into different classes [1]. In trivial cases, we may be able to do this in two dimensions, in which case the "hyperplane" is just a line bisecting two different classes of data. It's easy to see how this can be conceptualized as a type of regression.

[1] http://en.wikipedia.org/wiki/Support_vector_machine