I'm running down the last stretch of road at the Escape From Alcatraz Triathlon, when somebody yells out, "Hey! COACH BRETT!" I turn to look and see who could possibly recognize me thousands of miles from home, catching a rock with my foot and then crashing to the ground. I ended up OK, with just a banged-up knee, but it could have been much worse.
It's accidents like this that can end your triathlon career, so it's worth working on avoiding them. It's even more important as we age, because looking back and behind you becomes more difficult. To clarify my point, car testers wear modified neck braces to simulate how hard it is for an older person to turn around and look for traffic.
Looking back for cars or the competition can really throw you off balance, so you ought to practice it often. The more you do it, the easier it gets.
Practice it on your own, and for details on how I do this in training, look for the detailed explanation in the ZenTri Masters Area (link on left).