It ultimately is the same as interrupting.
When you interrupt a induction/casting based skill (red animation on enemy NPCs) it sets them off balance. This is the same, only it's ranged.
Bow skill line has a skill that does the same, a morph of Poison Arrow i believe.

Cody wrote: »

if an enemy is using an interruptable ability, such as snipe for example, they will be stunned if hit by crushing shock.

yeah, because using a bow (snipe) is "casting" ...

This game has so many broken mechanics, it's not even funny anymore

you do know that beside light, sort of medium (not fully charged heavy) and heavy attacks, there are also skills, yes?
Some of the later do have a cast or wind-up time; i.e. you need to 'cast' that skill for a certain amount of time, which is where all that animation cancelling comes into play...

Snipe has a rather long 'draw' time (for lack of a better word), and can't be cancelled (making it worse than so many other skills) plus that you still have to have your target in view at the end of that time (or it cancels itself)

So all in all, it's actually one of the very few properly implemented skills; meaning works without this animation cancelling cr@p and only on a target in sight from start to finish.
Unfortunately, pretty much everything else is not using that mechanics, but that's a completely different story.

Most non-"instant" attacks can be countered (light, heavy, skills) with an interrupt, e.g. with bash (in melee) or skills like venom arrow or crushing shock (on spells). Only non-"instant" skills can be interrupted this way.

Nothing of that has anything to do with how much damage that skill has or not.

However, a snipe attack is a physical attack, while the tool tip explicitly states "Interrupts spells, putting the caster off balance."

So yeah, "nothing broken here", ROFL.

Another thing to keep in mind is that just like bashing, Crushing Shock will interrupt any casting boss(unless he's not supposed to be interrupted - like not gonna work on Nerien'eth big skull throwing) but since bosses are immune to CC they will not get stunned.

As been said, interruptable skills are pretty much any(with some exceptions, see Nerien) that have a cast time/are a channel. Damage spells, bow heavy, healing etc. If you can see it charging you can 99% interrupt it with Crushing Shock.