Koresh would have gone to jail, or commited suicide. Of course, it would have been much easier to arrest him on his morning jog or bicycle trip to the store before the whole thing began.
If Koresh escapes the fire, then he will also be looked upon as somebody who bailed out and abondoned his followers. That might make him more of a bad guy than, well whoever you think started the fires. Of course, if he escapes, he might explain that his people did not start the fires.
Additionally, he might be able to give more detail about how he tried to surrender, and about how the, ummm, nice law-enforcement people accidentally ignored this, or about how .308 rounds kept coming through the roof, from the "observer" helicopters.