Anytime I have had to bring my car in for something where they need to change fluids, I always bring in the stuff, since I am afraid they will just dump in whatever they have lying around.
If they were repairing your car and the shop was very dusty, they may have had the radiator out, and at the same time the hoses were dangling there and the cooling system was opened and exposed to air.
I am wondering depending how serious the accident was that there is a chance you could have a cracked cylinder head or something is getting in the cooling system, they may have put an all makes and models coolant or if they used an aftermarket Dexacool like Prestone it could have a different smell.
My Dad has a bottle of the Prestone Dexacool at home, I will take a smell of the stuff and let you know what I think.