The Jbox is NOT screwed to the T&G (that's 9 inches above, I guess it's a little hard to tell from the pic). It's screwed to the plank on the left and right by way of the knock-outs and a few really big washers. The planks were toenailed to the adjacent joists and did not connect to each other - just the JBox.
I hate to see what would have happened if they hung a light fixture that weighed more than a pound or two.
I hate to see what would have happened if they hung a light fixture that weighed more than a pound or two.