An employee was operating an excavator to clear trees when a tree shifted in the bucket and broke through the front window of the machine. The tree came in contact with the travel controls, pushing them into the forward position. The machine moved forward farther into the tree, causing it to go through the cab and forcing the employee out the back window of the machine. The employee then attempted to re-enter the machine to shut it down. At this point, the moving machine caused the moving branch of the tree to strike the employee's left hand, smashing and lacerating the ring finger. The employee was hospitalized and had surgery.