Dumbest,,,, well too many to pick from so I'll pick the one I have some pictures of to help tell the story.
I had this large rock that I wanted to move to use in some landscaping I was doing. I tried to get it in the bucket but it wouldn't fit. Now as a reference to get an idea of its size, the bucket is 5' 6" w and 2' h. So since it won't fit in the bucket, no big deal, I'll just tie it up and hang it from the bucket, as you can see in the first picture. The picture was taken right where I picked up the rock. Now I've carried more weight than that in the FEL many times so no big deal, nothing to worry about right!! The second picture shows the road where I'm going and I'm going to go up the hill to the right. Notice the ground slopes down from the road. Now I get going and since I'm not aware of any danger I turn to the right and approach the road at an angle.
OK everything I'm going to describe in the next paragraph all happened within a few seconds.
So when I get to the slope on the side of the road, naturally the tractor tilted to the right. Since the FEL is up high (see I'm thinking there's no weight in the FEL the weight is near the ground) the FEL swung to the right. Now when that happened the rock which is hanging like a pendulum, swung to the right, and since the rope was not attached to any fixed point but just looped over the bucket, it was free to slide to the right. Ok so here's the picture, tractor is on a slope leaning to the right side, FEL is up higher than it should be, massive heavy rock hanging now from the right side of the FEL outboard of the right front tire. Oh but we're not done! The next thing I realize is that the left rear tire is lifting up off the ground, OH NO BOTH rear tires are lifting off the ground. And it was at that instant that it hit me that I had removed the backhoe and only had the box blade for counterbalance and it wasn't up to the job and my tractor was in the process of doing a one handed handstand on the right front tire. I quickly slammed the FEL control forward which dropped the tractor back onto all four.
Its really spooky when your tractor does something to you that youre not expecting. As Ive always said, Its the ones you dont see coming that'll get ya.
99% of the time I have the backhoe on and thats the configuration Im use to.