No, it wasn't accidental, it was on purpose. He uses the CS to make balls on females, collects the pollen and pollinates select females in isolation rooms. In the meantime, he keeps all of the turned plants in a room together since he isn't planning on pollinating them and selling those seeds, therefore they don't need to be isolated. They inevitably got pollinated from each other and made seeds. He could have just thrown them away, but he decided to give them out to us for free. We don't care if we don't know who the daddy is. They will still be fire.
At least I think that's how it happened. Someone please correct me if I'm wrong.