That's scary for sure. The most interesting moment for me was when I was mowing with the H. I needed to run into the house, and parked the H in Neutral, engine on, with the brake on, on what I thought was level ground ( knew it really wasn't, but was in a hurry, and the tractor wasn't moving). I looked out the kitchen window a minute later to see the H rolling down toward the edge of the woods with a little gully, some HUGE rocks, and what used to be a pond. As I tore out of the house I had visions of the H on its side in the ditch, engine still on, and how the heck was I going to get it out of there? Luckily it didn't have to much momentum (it really wasn't that much of a slope), so when it hit the first rock it just stopped without tipping, and I was able to just back it out. But my wife really thought something was wrong when I tore past her at top speed with a look of sheer panic on my face. Now I make sure to stop on level ground.
Also, I was filling in a hole on a slope, coming in from the top, straight down. I had nothing on the back, as I was in the midst of a million things, and needed to tow the log splitter next. Anyhow, I came up with a full bucket of dirt, start heading downhill with a light rear end. Things got exciting quick, as you can imagine. I wasn't skidding too bad, so I dropped the bucket, dumped the dirt, then engaged the 4WD and slowly backed out. Then I put my rear blade on. Both times I could have avoided the near disaster, but was in too much of a hurry to bother. Luckily I learned my lessons with no damage to self or others or tractor. Just a warning to always be aware.