Test Drove A Turbo'd Optima.

Hello,

So, my mom bought a Kia Optima...I think it's a 2011?
It's a single turbo'd 4-cylinder.

Anyway...I took it for a test drive.
To my surprise, it had some nuts.

I did a couple of launches in it, and the launches left me confused...
I held the brake, got the RPMs up, and let go of the brake. Instead of sucking you into the seat, the car would stop dead in its tracks. About 1.5 seconds later, it would start accelerating.
Is that normal for a single turbo'd vehicle, or no? (Never launched another single turbo'd vehicle, so I don't know.)

I only messed around with her car for about an hour. Never touched it since.
A week and a half later, her turbo blew out.
Did I cause this? Or were the weird launches an early sign of the turbo dying, or what?