As you can see, the Golem is at full health, but he's not built! The way this happens is that the Golem regenerates even when he's not done being built, so you can have your Initiate begin the ritual and then leave, but the Golem will continue gaining HP at a regen rate of 3. The Initiate can then come back and finish the job. The problem arises (as far as I can tell) only when the very last HP is gained without an Initiate working on it. The Golem will be at full HP but it is not finished being built, so it can't move or attack. I tried sending my Initiate back to repair it, thinking that might work, but since it's at full health, he wouldn't do it. Maybe if the Golem got damaged, then it could be repaired and finished, but that didn't happen during this game, so I have no idea if that would work or not. Either way, I'm fairly sure that this is not supposed to happen.
Edit: I doubt any of the following will actually matter, but just in case: Glest 3.2.1, Windows Vista, Intel Core 2 Duo