Forum:A little question of Alien

After the activation of "A" Cell Scatter Burst can I use snake whistle? and Can I use snake whistle after someone destroyed an Alien warrior of mine by battle?

I ask this questions cause I was looking at snake whistle rulings and it says that the last thing that got to happen is the destroyed monster and I really dont understand that cause I put counters after is destryed this means the last thing that haappened was the counter stuff?