Well it is a balancing game. Do I sit and hope no predator (you) sees me or do I make a run for it and blow my cover?

You'll find that the choice a snake makes will vary depending on location, and temperature of the snake/conditions.

Wayne says his wild snakes are "bored" but what happens also depends on numbers. A big cluster of snakes all together and below optimum temperature will make all of them more reluctant to flee. The one that flees from such a situation might be the first and perhaps the only one to get "picked off".

Any snake that is well below optimal "fleeing" temperature or too far from the nearest "for sure" cover, may opt to sit still, even for photos, (haha, better than sitting still to become a meal) and be very reluctant to flee for cover.

Again, it's all dependent on temperature and conditions. Location because what threats are present at that location will vary too. Just like the Galopagos island birds will just come and land on you. They don't see you as a significant threat. Not so in other locations.