Currently, it is possible to stand between 2 cogs and only one of them will shock, while the other completely ignores the player. However, if one of the cogs gets destroyed, the adjacent cogs can now shock the unit normally. This can also be seen when the cogs expire. When standing between 2 cogs, the 2nd cog shocks the unit as soon as the spell expires.

This indicates that the shock areas are blocked off by other cogs, leaving these safe gaps between the cogs.

To repro this, just position your hero between 2 cogs. One of them will zap you, but if you go back to that same spot, the second one will not zap you, unless you move too close that cog specifically.