This happens more frequently with oily woods and also if there is a thick build up of CA on the blank and bushing - when separating the bushing from the blank, the CA can raise up. In your case, unintended lateral pressure probably did it, or gripping it with some kind of pliers with a good protective covering between the pliers and blank. With that big of an area, it looks like pliers with the covering deformed it just a smidgen - and that is all it takes.
As mentioned above, it is best to remove the CA, and in my experiences remove ALL of the CA from one end to the other. I turn mine off with tiny bites with a scraper but a skew will also work. It may not seem to be necessary to remove all, BUT if CA is left on in portions that did not lift up, there will be a faint color difference between where CA was NOT removed and where it is removed - and you will probably see that after you re-finish it.