Okay, so it happened again.
Phillip K. Dick had no hand in Johnny Mnemonic. The original short story was written by William Gibson.
I don't know how I missed this because I even went to the Johnny Mnemonic page at IMDB to look at the writing credits, but my mind must have clouded over Gibson's name and replaced it with Dick's.
The mind does funny things at 1:00 in the morning.