Sentence:  Indeed we should say , on the contrary , that the accident of our later discovery made no difference whatever to the badness of the animal 's pain , that it would have been every whit as bad whether a chance passer-by <WSD>happened</WSD> later to discover the body and feel repugnance or not . 
Meaning of the word marked with <WSD> tags:  happen, occur, or be the case in the course of events or by chance