Helping my uncle fix a xj8 and when inspecting the cylinder head there was the piece of metal that contacts the cam lobe was out of place! I'm wondering why this happened. Thanks for any insight.

 

If the valve was bent I guess that would create ebough of a gap between the lobe and the bucket for it (valve shim) to come loose. You are supposed to use air to remove them and NOT a magnet- I suppose this is the reason