Sure looks like a lightning strike to me. How close to the house is that?
A friend of a friend had a tree hit by lightning out in their yard. You can see the burn line going around the bark in a spiral as it traveled the length of the tree. Like somebody had sprayed it with spray paint trying to make it look like a candy cane.
Rule of thumb is that when you see it, you count out the seconds until you hear it. If you hear it before you get to five, your life is in extreme danger. One of the kids I went to High School with died on the top of Half Dome Yosemite from a lightning strike. No warning, it just hit out of nowhere!!! If I see lightning anywhere in the sky when out mowing or working on the land, I call it a day and get indoors.
I've had several strikes so close to my house that the flash and boom where at the same instant. Shakes the house type of boom, but for the life of me, I've never been able to find where it hit.
This past Spring, the guy I buy my hay from was driving down Interstate 20 at the speed limit, 75 mph, give or take, and his two month old one ton Dodge duelly was hit by lightning. It basically fried all his electronics and wiring in the truck. He is under warrantee and he has full insurance. So far the dealer has put $20,000 into the repairs and it still isn't right. He wants a new truck, but nobody is listening to him.