This is why I always carry my H&K .40 when I hunt on my side. I also have an old remmington 870 20 gauge pump youth model that I sawed off, took the plug out, and keep loaded with 5 rounds of buckshot that I carry in my hands when I go to my stands and come out. Any deer that even twitches gets a load at point blank. Im not having a 150 pound animal come to on the back of my 4wheeler.
I am just gonna come out and say it. Any hunter that doesnt carry either a sidearm or a shotgun with them when they hunt is just stupid. I have shot rattle snakes, bobcats, coyotes, and anything else that might send me to the hospital when going in and out of the woods. Even if you never need it to defend yourself at least putting another round from a pistol or shotgun in a deer will make sure he/she doesnt run off while you go get your 4-wheeler or truck to haul it out.