Yes the concrete footings poured before the EC of his people show up are existing. After all it's there. If the EC does not have an existing contract, how do you tell the concrete guys to turn up a piece of rebar?
The only hope for this is the AHJ who may depending on local requirements inspect the footing before the pour. Rarely is this an electrical inspector. It would take the AHJ to make sure that this happens. Personally I doubt this will happen untill some one makes a big enough problem for the AHJ in an area to cause it to be required in the code that covers footings.
