Stem clamped to steerer tube below the expander plug insertion depth. Bad stuff...nothing reinforcing the inside of the clamp area. Given the length of protrusion, I don't believe that there are expander plugs that actually can insert that deep that the top cap will still be able to engage.

Most manufacturers publish safety notes with CF steerers that specify how much steerer tube should protrude. Depending on the tube and the specs of the plug, it's either none, or up to about 1 cm. They are usually pretty specific about it too.

If it's an alloy steerer, it doesn't matter.