The true origins of this list are somewhat mythic, being largely based on the collective experience of many hackers in the early days of building distributed systems. Peter Deutsch is the one who first enumerated them as a clear way to frame thinking about why distributed systems are fundamentally different. He says the following on his home page:
I first published the "8 Fallacies of Networking" internally while working at Sun Microsystems Labs in 1991-92. (The first 4 were originally described by either Bill or Dick Lyon; I added the other 4.)
I'm pretty sure that Tom (Pugs) Lyon had a hand in the list too.