Just eyeballing, the length of the bent tab, it looks ok.. but.. on a "factory" spring, I can see a very small stress riser from the spring winder tooling at about the area this one broke. (!) I don't know if I can get a picture or not, I'll give it a go.
When I wound the springs on the lathe, that wouldn't be there.
Edit: Ok, here ya go. I'm betting the tool needed to be polished.