Enemy is losing 2 health instead of 1

What makes you think the enemy is losing 2 health instead of 1? Is it that their health bar goes down to 1, rather than down to 2? Or you have you looked at their Health component in the debug view and confirmed it is currently at 1?
If the enemy takes damage in this way twice, does it die? Or does it correctly take 3 times?
I ask because you're calling takeDamage.EnemyTakeDamage and healthBar.SetHealth, but sending damageAmount through to both.
The code looks like it should be dealing 1 damage via the takeDamage component, and then setting the health bar to 1. Rather than setting the health bar to the current value of the health component.

/r/Unity3D Thread