The statute of limitations in Ohio for personal injury is actually two years. Ohio Rev. Code, Section 2305.10. So, look at the exact dates involved. Unfortunately, if he's been living in Kentucky for awhile, the statute stops running, because he's not in Ohio to be sued there.
Assuming that it hasn't, the employer is vicariously liable for the negligent acts of an employee that occur within the scope of his business. That means that if the judge finds that your son caused the accident, the other party will get a judgment against both of them and will likely try to collect it from the company, not your son (since the company is more likely to have money).
If he was covered by insurance at the time that this happened, he may want to contact and notify the insurance company - they should cover it. They should also produce a lawyer to help him, since they have to pay if he's found liable. So, the first step is to call the insurance company.
The employer actually has an interest in showing that your son didn't cause the accident since, if he did, they have to pay. But they won't necessarily help him, because an employer in this situation can defend by saying that the employee was reckless, or not working - essentially, they can try to distance themselves from him. So, it depends on the specific facts of the situation. Their attorney could find that they have a common interest and defend both of them. If he knows who their attorney is (or after an attorney files an appearance in the case), he could try talking to that person - as long as he is careful in what he says and does not admit to any wrongdoing.
He does have to file a response before the deadline or he'll be presumed liable. If he isn't able to get an attorney before the deadline, the way to do that is to go through each of the allegations and address each in turn, admitting or denying them (or saying that he doesn't have enough information to admit or deny them). He can then raise any defenses he has, such as the statute of limitations or the negligence
of the other driver. This example has some samples of the language typically used and some common defenses.
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