That doesn't look like corruption to me. You just resized the formula bar.

If I did, it was by accident. And it then did the same for every tab, and XLS, and exiting of Excel, rebooting, repairing - everything. I tried dozens of things to try to correct and none worked... except full reinstallation of Office.
And if it happened again, I wouldn't know the cause, because all I did was copy a cell intending to paste it somewhere else, and then boom it happened.