Jocko is quite right, there is no need to remove the shaft to do the bearing. I think they pulled the spider out of the inner CV joint and therefore had to remove it to put it back in.
Also, I can see why an incompetent would grind it. On fitting the replacement I found it would only go half way into the diff and then stop. Looking into the diff, there is a groove in the splines, so if the shaft is not perfectly aligned the end of the shaft won't go in. It needs to be wiggled about while being tapped with a soft hammer in order to get it go right in.
In addition, the clip has to be centralized in its groove as this will also foul the inner groove. I held the clip in place with grease. I suspect the idiots working on this car could not work this out, so butchered it instead.