Well, it happened to me this evening. Ran over a small branch, but it was big enough to cause the blade to slow and light go yellow. Then noticed the mower is a little louder with a small vibration. Yep, bent motor shaft. I'll baby it along this summer, but I know it is now just a matter of time before I have to dig into the wallet again. Nobody's fault but me and mother nature. Just a bit depressing. It must have hit funny, because the blade is still sharp with no hard "dents or dinks" from the stick.
Note: This would happen with any mower. Gas mowers vibrate so much to start with that you don't notice slight changes. The EGO is so smooth that you notice it.