At 00:30 on Dec. 26th, a crash awakened Julie (and me, eventually).
Inspection revealed the Christmas Tree had fallen.
We have an annoying cat who doesn't stay away from things and has been batting ornaments ever since we got the tree.
The tree was taller than last year's tree.
It was cheaper than last year's tree, perhaps indicating that it's wood was softer.
The tree stand is (now: was) one year older than it was last year and less maneuverable and still as small.
The tree has been leaning a little more every day.
It fell in the most convenient direction for cleanup, meaning the most accessible direction. This was also the direction where most ornaments were hung, probably because it was the most accessible direction.
Other facts, less relevant to figuring out who did it:
The cleanup took about 45 minutes.
The carpet is finally dry, but still a little warped.
The needles are still everywhere.
We think we got all the ornament shards.
We appreciate that it didn't happen during the previous night.
The tree now resides in the street in front of the building.
The tree stand now resides in the garbage.
The cat still resides with us.
Conclusion:
The cat probably did it.