That is a curious scenario considering:
Elephant seals are solitary in the ocean, but on land they form large colonies around their breeding grounds. These heavy animals are best adapted to the sea and clumsy on land, but can move at speeds up to 5 miles per hour if threatened.
https://animals.mom.me/fast-can-elephant-seal-move-land-2954.html
The average running speed of a "healthy" adult human is probably somewhere in the range of 10-15 miles per hour. This would be a measure of the average "peak" speed of every healthy adult human on the planet, regardless of gender, age, or size.
https://www.quora.com/What-is-the-average-running-speed-of-a-human
Perhaps the fleeing fisherman isn't physically up to an extended run or didn't have the time to evaluate his escape route.