Landlord damage dispute with tenants

I am a landlord. I found two dents in the driveway of my rental house. Therefore, I had a professional estimate for repair ($500). I deducted the $500 when I refunded the deposit to the tenants. Although the dents are obviously caused by one Van parked in the driveway for long time, I have to deduct $125 for each of them since 4 guys (friends) rent the house together as a group.
One guys claims this is normal wear and will bring me to the small claim court.
Do you think this is normal wear? Do I need to deduct deposit from one tenant who caused the damage or deduct equally?
Thanks.