Honestly, your buddy did the right thing by acting quickly and minimizing his footprint. I've moved turtles off roads and always step just far enough to ensure their safety, then immediately return to the path. That brief departure is justified when it prevents harm to vulnerable animals!

What about emergencies that don't involve people? My buddy once had to leave a well-marked path because he spotted a baby bird out of its nest, right in the middle of the tread, with a hawk circling overhead. He stepped off exactly three paces, placed it gently under a nearby shrub its parents were chirping from, and stepped right back on. The whole thing took thirty seconds, but he still feels conflicted about those few feet of crushed grass.