Engine/tran separating

I have a 2001 xj. The other day when i started it up, i heard a loud tapping sound and then the engine started to seize up. I went under the jeep and noticed my engine was separated from the trans in one spot. I tightened up the bolt and the jeep started back up. My question, does anyone think there could be damage to the flywheel, trans, engine from the separation when i started it? I dont feel like dropping the trans to find out. Been real busy lately.

One flexplate bolt or one bellhousing bolt?

One flexplate bolt would make a hell of a racket, but not much chance of damage. If one flexplate bolt was loose, you need to tighten the others.

One bellhousing bolt shouldn't have even been noticeable.