I have no idea why people are giving the OP such a hard time here. He's just considering his circumstances and trying to make sure he's prepared, like all of us do.
if I had to leave w/o my bag, I would have my Kershaw Chive, Vic Farmer, SW 637, two speed strips, OC can, keys w/ vic Gigabit tool and my wallet.
The main thing I see missing is a flashlight. A Fenix P2D is small enough to disappear in a pocket. I would definitely add a light of some kind.
You didn't mention how far the walk home would be, or in what kind of terrain, though this could influence what you'd want to have with you.
You also didn't mention whether you have a car parked downstairs with more gear. I guess if you are concerned about walking home then there is no car...
Working in an office where weapons can't be noticed, and "gear" seems unnecessary (to the sheeple), I've worn this belt pouch:
http://www.rei.com/product/757666 (in black, with the shoulder strap removed). In it I carry my cell phone, business cards, 2XCR123 flashlight, folding knife, multi-tool, OC, pad of paper, pen, case w/10 cigarettes & lighter, 3 spare CR123s, and could add quite a bit more if I needed to (am thinking about a spare set of keys). It's not the absolute sexiest bag I've ever seen, but it doesn't look bad, doesn't look "tactical" (like some of the Maxpedition pouches do), and conceals everything well while keeping it accessible. If anyone asks what's in it, I just start listing off the non-weapon items, in a way deliberately intended to bore them, and no one's pressed it. I suppose if they did I could just go on about how cool this flashlight is, etc. I keep the things I'm most likely to need in front of people in different pockets (of the pouch) than the things I don't want them to see, so no one glimpses my knife when I'm grabbing my phone. It's the only thing I wear on my belt, and with all the electronic gadgets people regularly carry nowadays, a small pouch on the belt that is not obviously a knife sheath really doesn't get much attention.
I could walk out the door with what's in my pockets and what's on my belt.
Go to an REI type store, or even camera store, and look at belt pouches, find something you can get away with, and then see what you can fit in it.