Because of the shape of the Bullet, it is unlikely that you have damaged it. The shape is designed to let the air escape in a mishap like this.
In future, if it looks likely to power into the ground, take a couple of steps towards it. This will take some of the sting out of it.
Because of the gause it is difficult to see inside, but they are very well built kites.
If you are still worried, take it along to your dealer who sold you it and get him or her to check it out.
After all thats what they are there for, the after sales service, not just the initial sale.
TYKE