It was part of the security program the business man put into his brain. I don't remember the exact details but after writing the program for taking over Elysium the computer asks him what kind of safety measures he wants for the data and he picks "lethal" rather than "non-lethal."
So they did show it in the movie but since he was sitting at the computer alone and didn't really talk to anyone about it.
"Hi Bob, guess what? I just put that lethal DRM software into my brain. You know, just in case someone tries to hack my brain. MWAHAAHAHAA! Anyway, how is the family doing?"
it is easy to miss.