sometimes plants do shit for their own reasons, even the most careful and skilled growers will get a little hermi goin on, or find a stray seed, dont sweat it so hard.
if you grew bagseed they might have been seriously predisposed to hermaphroditism, and they could have grown balls no matter what you do.
a few seeds wont ruin your dope, in the 80's gettin a sack without seeds was a miracle, but all that seedy weed still smoked good
i would not try to grow any of the seed you develop from these plants, if you cant figure why they hermied, they prolly did it on their own