Thanks all for weighing in with your opinions. The mentioned fish is now in my forage fish pond. Hopefully it'll get huge and I will catch it again, maybe then we can get a 100% sure ID. I am 99.9% confident it is a male. So, it shouldn't cause issues I hope regardless of parentage...
My guess is it is a natural BG male x GSF female cross. However, how can anyone say for sure without checking gill rakers and maybe even DNA testing? It sure is fun to look at unusual sunfish hybrids and make guesses though.
Also, if you are interested in crazy sunfish hybrids, check out this
thread.