After you shut down the gas, Quinn will call and tell you he is bailing on the messed up scene, and that his shop is open for you to ransack.
If you do head back down to his shop, in the back room you will find a terminal with two crates stacked up on top of one another. Move them, and you will find a switch. Press it, and Quinn's secret stash will be open for your enjoyment.
HOWEVER, if you are going for Factory Zero, you will notice nearly everything is useless to you
. Get the energy bars, painkillers, and the hypnostim, then go beat the snot out of Burke.
Questions, corrections and neg vote justifications below.