I can believe it if it was thinnet coax. The actual specs are for 59AU and one segment with the wrong cable can cause signals to get screwed up.
I added one computer at the end of my thinnet network (several years ago) using 5 feet of AU and other machines on the network disappeared. Turned out I had some 59U in place, sold by Office Depot for thinnet, but not shielded the same, and I didn't notice it while the network was working.
Any computer on a thinnet network with the wrong cable would be capable of creating a broadcast storm that could feed back into a broadband network.
The problems are the result of signal reflections from impedence mismatch. Just moving the cables can sometimes cause nodes to disappear. I've fought a couple of those.
Ed Fair
Give the wrong symptoms, get the wrong solutions.