Spring Plate Failure (Almost)

This is a Public Service Announcement: front strut mounts must be assembled a certain way. When disassembling my front struts I was curious why there was this groove cut into the upper spring plate:

Obviously this was cut by the upper strut bearing but there should be no contact between them.

Flipping the spring plate over and there is a similar groove cut on the underside:

I didn’t see the various parts when the strut came apart, parts scatter when the spring tension is released, but my theory is that the lower washer was installed on the bottom of the plate instead of on top. Putting it on top would space the strut mount higher and it would not contact the plate.

Here is how it looks in the official parts diagram:

#2 is the washer that ended up on the bottom. #3 is a sealing washer for the bottom of the bearing. #8 was also missing.

If this had failed when driving the spring could have slammed up over the mount and into the strut tower. Scary stuff!