Don't worry. You won't even noticed the snare. Especially not on a stam toon.
That might be true in sense. In reality casting a snare removal and immunity skill does not always remove the snare nor does it always grant the immunity. Which lead me to double cast a skill.
For players I think it is due to the lag, but on some npcs it is 100% chance it just does not work against them.
Moons and sands shall be your guide and path.
PC EU/NA