I have to do it more often than I'd like on my property. I am _VERY_ careful not to ever be directly in line (in front of or behind) where I'm cutting, so that if it drops or barber-chairs I'm not directly in the way. I try to have multiple escape routes planned and I take off at the slightest movement of the tree.
I had a funny pinch earlier this past fall. There was a dead pine standing perfectly straight with no branches. It was probably only 8" diameter and about 20-25' tall. I cut a shallow notch, then made my felling cut. I cut and cut and it never started falling. It was soft wood, so before I knew it I had cut all the way into the top of my notch and I felt a little "thunk" as the tree dropped a fraction of an inch and pinched my bar. I shut the saw off and stepped back. I had cut all the way through but the tree was standing perfectly straight with my saw (just a couple weeks old MS 261:irked: ) pinched in the cut perfectly parallel to the ground. I thought about it for a minute and decided that because it was a small tree and not that tall, I'd approach carefully, grasp the powerhead of the saw and twist it slightly. The tree started to fall in slow motion and freed the saw. I took a couple steps back (135 degrees from the direction of the fall) and as the tree got to about 10 degrees from vertical it fell into a pile a few feet in front of me. It hadn't realized it, but it was so rotten that it couldn't support its own weight.
Once I changed my underpants, I was checking out the remains of the tree. No section bigger than 6' was left. They were so rotten, I could kick them in half. I walked over to the stump, and pulled it out of the ground with no resistance! I could crumble most of the tree with my bare hands.