Alright took a look, that is the lower coolant hose (or rather the coolant temp sensor, CTS, flange) where it attaches to the radiator. It is directly across from the drive belt. It looks like while you were moving the car with the bolt out (bad idea, but you didn't know and I didn't know this could happen), the engine moved forwards enough for the drive belt to make contact for an extended period of time. The friction wore through the thermal plastic of the coupler (that is spelled wrong I think but google won't fix it for me
) enough to cause a pin hole leak. You can see it in the photo. This would cause a stream of coolant to spray on the engine and drive belt. Which would explain the smell.
If your tech hasn't looked, or mentioned it, I would have him examine the drive belt and probably replace it. It might be coolant soaked and or compromised due to wear.
Edit: Sorry for the beef, didn't mean to insult your tech, thus the edit. That being said it took me longer to type this edit, then to figure what happened and be able to explain it to my wife
.