12vdc vs 24ac mis wire off CCTV camera

I have mis wired a 12vdc camera with 24v AC . The owner provided the camera and had misplaced the installation instructions, She did state it was 12 volts but did not the state that the other 5 existing cameras were 24vac. The 5 cameras had their own central power supply and she also stated that this would supply the new camera as well. At the power supply,which has fuse protection for each outgoing 24vac circuit, it did not state the voltage. This work had been installed by others. When the new camera received the wrong voltage it damaged it. (Repairable for $55) but the homeowner claims after the fact that 4 of the 5 other cameras are now not working. Calling the mfr of the new camera, Tech help said that the "wrong voltage " issue to the new camera should not have affected the other now non working cameras. I'd like to think that also but the coincidence seems very remote. While the problem was developing the homeowner was constantly plugging in camera feeds between her old DVR and a new DVR,

?? Anyone with ac/dc circuit knowledge that can explain how the a/c to the DC camera could have caused the problem with the 4 other cameras? Would it not be expected that the small glass fused protection worked and should have blown the fuses should a short, or whatever came back to the power source? Hindsight is 20/20 I know, I would have done things differently had I envisioned the upcoming issue. As the homeowner bought the wrong camera for her existing system and failed to provide instructions and stated to me this was a "plug and play" installation. I'm on the fence as to how much I'm responsible for what's happened. I'm a retired electrician and the home owner knew my lack of experience in CCTV camera field. In fact I relied on her knowledge to guide me in what she wanted. Still I feel bad that I'm involved with this issue. Any information or thoughts by others in this field much appreciated.