I don't think Ahern was referred to here on ET as Bertie in other than a deprecatory manner, though not for the reason you state.

I'm curious because I have observed this phenomenon about male/female first/last names in many contexts for a long time in various countries...

En un viejo país ineficiente, algo así como España entre dos guerras civiles, poseer una casa y poca hacienda y memoria ninguna. -- Gil de Biedma