From the Rhodes.edu website:
"Former Olympian Dave Wottle, who now heads admissions at Rhodes, is a master at goal-setting. When he found himself dead last in the beginning of the 800-meter race at the Munich Olympics in 1972, Wottle set a goal of simply catching up with the pack. He didn’t want to embarrass his friends and family back home.
Within seconds, however, the gawky runner with the golf cap had accomplished that goal and set another. “When I passed the first Kenyan (one of the front-runners), I quickly reassessed my goals and decided to go for a silver medal,” says Wottle. And when he edged ahead of the No. 2 runner, another Kenyan, his goal shifted upward again. He went for the gold."
I've read more detailed interviews by him saying much the same as above. To suggest that Dave was totally confident in the success of his strategy, or was even deliberate in his strategy, may be generous. It certainly appears, from the paragraphs above, that he was hoping, at first, to just not embarass himself on the world stage. His trials success (winning and setting a world record) was apparently unexpected and recent, suggesting that he may not have been too confident in the event.
However, that first paragraph above could be thinly veiled inspirational stuff (set a modest goal, and then set new ones, and you'll be a winner in life as well...).
No getting around it though, Dave was and is a Man.