Apparently not.
You can just see at the top of the picture why the bluetit is getting out of the box in such a contorted way.
Suddenly, it's into the attack!
For a brief interval, the two birds lock claws(?) on the roof of the box ...
... before tumbling off it ...
... and then separating as they drop down.
This time, I think the nuthatch really did go away.
The rather battered looking bluetit spent a short while recovering on the entrance hole before he, too, left for other things.
I would never have thought the a bluetit would take on a nuthatch - and if it did, even less would I have thought that he would be the victor!
Finally, a picture of a bluetit in Box3. We haven't entirely given up hope for this box again this year, but visits to it are few and far between.