Re: Was there no conduit?
No. That is wrong.
Cables must be loose - that is, not-fixed in position - or must be protected by trunking. It is not possible to drill into cabling where it is correctly installed* - barring switching drill bits and persisting until you get through the trunking.
*Well, except right next to sockets, switches, etc, where the cable is held by the socket, switch, etc. But there you can take the faceplate off and see exactly where the cable is, move it aside, and so on.
There are also rules about how to run cables, but they're belt-and-braces compared to how to _install_ cables.
If you do manage to drill into cables, it is almost - 99.99%+ - certainly a dodgy installation. Even idiocy of a high degree is rarely enough to manage it in a compliant building.
Biting the hand that feeds IT
