Yes, there was self-deprecating sarcasm there.
Just because dumb people who don't understand what they are saying misstate an idiom, which then gets repeated by other idiots, that doesn't mean that the newly-fractured version is now the idiom.
In this case, the actual idiom is "six of one, a half dozen of the other". Anything else is the result of what I just explained above.
"And there went out a champion out of the camp of the Philistines, named Goliath, of Gath, whose height was six cubits and a span." - I Samuel 17:4