Two things:
Run the Carfax (cheap)
Ask if you can have alignment checked. If he balks, you walk. Have the rear checked as well.
This is peace of mind for $100
If it was a side swipe, then you should be in good shape. The Carfax should have a description of the accident.
**One thing bothers me. If the Ins Co uses a method of 75% damage, Let's say the value was 10K. Where is the 7500 of damage at? Def have the alignment checked. If it ran for 20k miles after the accident that is where the pain would be. However, every adjuster and customer is different. I have seen them totaled when they should not and visa versa.