More than somewhat.
Cpcs have been mandatory in lighting circuits for 50 years, and there is no way that wiring is that old.
So whoever did that either had no idea, or did not GAS, about complying with the regulations.
An ignorant, or recklessly dangerous buffoon like that doing electrical work? What other horrors might he have perpetrated?
Mark - in this case "working" has the same connotations at "arrived safely" when talking about a trip in a car with no airbags and not wearing a seatbelt.
I cannot urge you too strongly to have your entire installation properly checked and tested as a matter of urgency - it could just be waiting for the right opportunity to kill someone.