He oughtn't to / shouldn't have done that. 他本来就不该做那件事。(可是做了)
5)“would + have + 过去分词”表示对过去的某种情况进行猜测,或本来要做某事却因某种原因未做成,通常用来说明某一情况,但不像用should或ought to那样含有责备之意。如:
I guess the poet would have been about twenty when she wrote her first poem.
Another worker wouldn't have acted like that.