Failed to follow code twice

upon construction of new home this business failed to put a central vac on separate circuit and also failed to put a disconnect switch at the AC unit, MB hydro made them add the separate circuit. Later the AC problem was discovered and owner said that the code did n ot require a Disconnect switch in 1994. He said that was the only year it was not required. I believed him and now in 2011 I am doing some work to the AC and have been told it was requiried by a real electrician.