"Well if you are a believer now, then you weren't an atheist for the right reasons, because the claims of theism still lack empirical evidence."On the surface, this is a No True Scotsman fallacy, that they were never true Atheists to begin with (it is ironic of course that the originator of the No True Scotsman, Anthony Flew, himself is an ex-atheist). Being an Atheist doesn't in itself really require any thinking, so you can be an Atheist with a poor understanding of why you are an Atheist. Whether such an Atheist can be defined as true is difficult to asses, since the only requirement of being an Atheist is not to believe in God.
However, in most people's view it is quite true that being an Atheist without knowing why means that you are not an Atheist for the right reasons, and it is furthermore true that unless there is any evidence for god on the table, then your reasons for caving in to religion are quite poor(so I agree wholeheartedly with BGH). So, there's no reason to be smug about your conversion and "former atheism" when it just shows you were in it for the wrong reasons.
So anyway, I decided to make a flow chart to educate people on this issue: