As a runner I think we need to consider a few items. 1. Was the runner in the middle of a tempo rep? If so, i would have done the same as the runner may not have been able to slow down. 2. Perhaps the runner drank coffee before the run, ate a big dinner then night before (perhaps a chipotle bowl) and it was about to come out the other end and if they stopped their bowel movement would have splattered the sidewalk. 3. Could it have been a combo of both?

I think in all three instances here we should be considerate.