Re: ..without using his network tech
You are right. non-switched hubs still used CSMA/CD. But that is why I specifically said "switched 10baseT and later". I have not seen an un-switched Ethernet hub for 25 years or so.
(actually, that's not quite true. I still think I have a 10base2 to 10baseT repeater somewhere which was not switched, but even that was rescued from the bin of one of the companies I worked for. I stopped using that when I stopped using 10base2 in the house, which was when I started using WiFi in about 2002)
Biting the hand that feeds IT
