Interesting topic. I have done two, one intentional and one weird one. Intentional was two does side by side, dropped them both with a 100 Hornady from a .257 Weatherby. They were three feet apart.
Weird one was the time I shot a large doe thru the neck at about 75 yards with a .223 Rem. 55 gr. Fed. round and a few seconds later a small buck came running down the hill from her upper right with blood streaming from his jugular - saw him drop also. That little bullet not only angled back to the right but deflected up, and the poor forkhorn was in the wrong spot at the wrong time. This happened in aspen cover near a farmer's yard - the guy was experiencing severe depredation problems and I had to kill some deer for some reason at the time. I had no idea the buck was standing up above me and the doe. I did know that there was not livestock and no people in the area at that time - I was essentially in the back corner of a very large farm yard. Thought the shot was very safe since there was a hill for a backstop, fairly open aspen cover and could see good behind the doe.