I used to get my first saw stuck all the time like that. Used to spend a lot of time getting it out, too. Then the tree was still stuck in an upright position. At that point I'd fire up the saw again, cut it the rest of the way from the opposite side (they often still stayed upright even when cut right through, due to tangling of branches with adjacent trees) and then I'd make another horizontal cut a couple of feet above the first one. When the second cut broke through the tree's weight would sometimes cause the loose 2 foot piece of tree trunk between the two cuts, to be fired violently toward me. I was dealing with bigger trees than the one in the pictures, and a 2 foot chunk of it moving at high speed was no laughing matter.
I seldom had much luck judging which way the tree wanted to fall. Most trees seemed to have balanced themselves over the years, and the main factor in which way they fell was the wind.
