He seemed very detached from what was going on.

這句話的意思更可能是“看起來他對發生什麽事毫/漠不關心”be/seem detached“（態度上）超然的，與己無關的”。seem這裏沒有主動表被動，就是簡單得系動詞，detached是ed分詞充當表語。

如《科林斯英漢高階雙解學習詞典》的解釋與例子：

1. ADJ-GRADED超然的;冷漠的;不帶感情的 Someone who is detached is not personally involved in something or has no emotional interest in it.

He tries to remain emotionally detached from the prisoners, but fails...他試圖不帶感情地對待那些犯人，但是做不到。

It is written in a detached, precise style.行文冷靜客觀，壹針見血。