I've dated black women, too...and my closest folks are black. But if I said somebody was "talkin' like they were black", those folks would have a valid reason to slap the shit out of me, because that's an inexcusable statement...and actually quite racial, if you ask me.
That excuse, in my opinion, is only used by folks that are trying too hard to be accepted. If you're about it, you don't need to make statements like that. I know people that have fucked and had kids with non-white folks, that are racist as fuck...have hatred towards their own kids for being "half-breeds". So saying you dated black women is completely irrelevant and should not be used to show how "accepting" and "non-racist" you are. If you live that life, and are neutral with all races, you'd brush that shit off your shoulders and let your mind and heart shine through actions...instead of trying to justify anything you say or do.
Just my 2 pennies.