Nearly the same thing happened to my dad & his fishing partner during a local club tournament back in the early 90's on Richland Chambers lake. The lake at this point in time was only a few years old ( Still grapevines, briars, & snakes in the tree's ). They were fishing in a heavily timbered section of the lake on a windy day. All of a sudden they heard a loud crack as a large pin oak fell about 20ft behind their boat. They decided it was wise to just leave after that. It pays to pay attention to your surroundings while on the water. Fishing is considered to be one of the most dangerous sports. More fisherman get killed every year than any other sport combined ( can't remember exactly where I head/read this ). Years ago on a tournament my dad fished on lake Whitney TX ( either Anglers Choice or a Honey Hole tournament ) one angler died due to a rock fall while fishing around some of the bluffs. He didn't show up to the weigh in so a search party was organized. They found his empty boat next to one of the bluffs & put 2&2 together; 3 hours later divers recovered the body. About 8 years ago on Lake Fairfield TX to guys in a brand new ranger running in the dense fog ( Power plant lake ) went over the dam; they survived without a scratch but the boat was totaled.
Freak accidents can happen but a little common sense along with paying attention to your surroundings can save your life.
Be safe on the water yall.