So you've never had an unexpected need to stop? You've never had a wreck happen in front of you which you had to quickly decide to either maneuver or stop instantly? No truck tire blow-outs causing debris to avoid? No animals darting in front of you? You just see it all coming, aye?

Most likely scenario being "bridging the air gap." For every voltage, a minimum distance is required between two conductors, keeping in mind windy conditions and other factors that can change the gap. Taking away three or four feet from the gap could easily be enough to short the two phases. That's a pretty horrible…