How to reproduce:

1. Open attached project
2. Open scene TestScene.unity
3. Select the TriggerDamageAtMidpoint game object
- In the Animator Window, notice how it has two animations: Idle and LoopingAnimation. They are both set to transition between each other.
- Idle -> LoopingAnimation has an Exit Time of 0.75 and a Transition Duration of 0.25
- LoopingAnimation -> Idle has an Exit Time of 1 and a Transition Duration of 0
- Also in the Animator Window, there is a parameter called StartLoopTrigger which triggers the transition from Idle to LoopingAnimation
- In the Animation window, note how the LoopingAnimation animation has 3 animation event points: RepeatStart(), DamageEvent() and RepeatEnd()
- Once called, the events should print in the console when they were called in the context of the current animation being played
- The repeating is controlled by the AnimationRepeater script
4. Play the Scene
- If the StartLoopTrigger was enabled before starting, the animations should start immediately, otherwise enable the trigger once.
- Notice how the console prints the events in order:

RepeatStart @ 0.25
DamageEvent @ 0.5
RepeatEnd @ 0.75
RepeatStart @ 0.25 <- Problem area
DamageEvent @ 0.25 <- Problem area
Then it loops.

This appears to be caused by the transition back to the Idle animation, as muting that transition causes everything to be printed properly, with 3 events per cycle.