Day146: How did this happen???

When I let the dog out this morning, I heard a squirrel scurry across the patio cover. I went out to see if it was throwing acorns at the dog and this is what I found. It had to be my photo of the day - because I can't explain exactly how it happened. It must have happened yesterday while I was at work, because I'm pretty sure I would have heard it hit. I know it wasn't like this over the weekend because I was outside with the dogs quite a bit and I'm pretty sure I would have noticed. It was hard not to miss. I think the squirrels have started group javelin throwing to protest the "squirrel hotel" next door being closed. What I can't figure out is the angle, especially since this branch had to have fallen from my huge oak tree from straight over the house. 

I have two repair people coming to give me quotes tomorrow on repairing the roof and someone coming to give me a quote on trimming up the tree that dropped the branch. I can't afford to have it taken down - it's probably 200 years old, 80 ft. or more tall and about 4 feet in diameter. The bad thing about it is it's only about five feet from the house.