I think my GDA topped herself

I have seen this happen before i don't think it comes down to genetics, my guess is it is like the tri-leaf mutation that randomly appears but doesn't go with the genetic code, if you had 2 specimens that did this maybe you could breed them and try to make it a more predominant trait, however i doubt it, orelse some strain hunters would've had gotten into huge fields to select just this traits and breed them in order to make a strain with the auto topping gene, same would happen with the tri-leaf, imagine ultimatly having a tri-leaf plant that would automatically top herself at every node and doing this on a 2 meter tall sativa strain to remove the only downside of the tri-leaf, that would give out some massives trees with about 200 colas.