Hiyo, here's my point of view. Do I think snakes know the difference between people? Yes. Do I think they favor people over another? Yes, but it has an addendum.

Like others have said many times over... the scent, movements, pressure, heat, vibrations, and finally how the person feels while handling them all affect how the snake feels about being held by each person.

Someone who is inexperienced may not hold the snake the same way as someone who has done it many times and instinctively holds the snake properly.

Someone who is nervous about holding the snake will affect the snake; just as someone who is confident and unafraid will often make the snake feel more secure.

Practiced hands are quick, reassuring, steady, and act almost instinctively. They don't hesitate, and are moving the snake in a way to hold him best.

Someone who is unfamiliar with how snakes move may find themselves trying to hold the animal back or stopping them from moving, rather than supporting the snake properly while they squirm and slither in such a way that the snake never leaves.

Again, I think it all takes practice.

This goes for all animals. I spend a lot of time with the rats. I can hold them differently and more effectively than Chris does. I have more practice. I would love to see him try to give them a bath without injuring them!

practice, practice, and practice.