Hmm very well could be.
Just suggested it because i had to kill off a plant last week that I had going since Feb. not sure exactly what caused the herm but there definitely were light leaks, and a few days before a friend had pulled onto my lawn and had head lights on while trying to back out and do something to his tire so the lights were on them for about 10-15 min during their dark., Also, porch lights within 200 ft and a street light (hps) within 500 ft. but theres also the fact that it was indoor since feb and light cycle had to be switched when transplanting outdoors, as well as it being a bag seed... Theres a million reasons itcould've been herm.,.. But I spray everything top and bottom with B.t. every week, Im out there at least 2-3 hours a day, I check and LST everything... and they still snuck up on me... Luckily nothing opened, But I mean, out of nowhere I saw a whole branch with tons of male preflowers starting, after it had been growing female preflowers for months... I had confirmed female so long ago I sort of let my guard down. Could be a blessing in disguise because Im growing 4 gorilla glue fems and GG is known to herm, So its sort of given me a refreshed outlook/vigilance to be on the look out just as everything is starting to flower.
I hope for your sake it is a herm as well, Maybe strike up a convo with the neighbors and see if they happen to bring it up (wouldnt even mention yours at all..) Good luck my friend. Cheers