Recessed Lighting under hot/cold supplies??
There are no clearance requirements from sources of heat such as can lights to copper supply plumbing. I would avoid touching them together, but there's no code-based justification for not allowing it.
If you wrap the pipes with insulation, be sure to have a good inch of clearnace. Foam pipe insulation will melt if it is too close to a can light, and that could cause some problems. Cans reach something like 190 degrees, which will melt plastics such as flexible ductwork if it touches. If you're insulating, be sure you use the correct can light with an IC rating.
The only supply plumbing that has clearance issues to sources of heat is PEX, and there are minimum vertical and horizontal clearances established by the manufacturers.
Sorry to hear your building inspector won't give you straight answers. If you need any code information, give me a hollar.