If I had cut that tree, and knew it was a leaner over a trail, and did not have it on the ground, I wouldn't sleep a minute until I finished, or hired somebody, to finish the job. I wish this thread was posted over on arboristsite.com, they'd have a cow for sure! Best thing to do is get a chain around it, below the notched cut, and I mean a LONG chain, and pull from the base of the cut tree, straight away from the stump, preferably with a comealong or winch. If it breaks at the notch, and the remaining stump plows into the ground, go back and get the chain around it again, and pull it down, straightaway from the tree it's hung up on. Funny things happen with trees like this, top branches snap, fly back, and kill unsuspecting fellers, or bystanders. Anybody that recommends cutting the tree the leaner is tangled up in, or anybody that recommends dropping a third tree into the the two that are standing, has a death wish.