My neighbor Bob did the same thing to me last spring when I was putting up a fence. He swore I didn't need to rent an auger, said a sharp shovel and some elbow grease would do the trick. Three posts later and my back was shot, plus two of the holes were so crooked the fence line looked like a wave. I ended up renting the auger anyway and had to redo all the digging. Now I just nod and smile whenever Bob offers advice, then I go check actual building guides online.

I read about a guy in a forum who said he keeps a roll of 4 mil plastic and a battery powered leaf blower in the booth for exactly this. He just covers the whole open doorway with the plastic and tapes it down, then runs the blower on low for a few minutes to push the dust out before he starts sanding. It's not perfect, but it beats watching your clear coat turn into a texture job. The latch snapping though, that is just bad luck timing.