Throwaway account. I'll try and keep this brief!

In April of 2014, I got into an accident while driving my grandfather's car. The damages to the other vehicle were covered by his insurance company. (I was also insured separately, but without doing some digging I'm not sure what my policy entailed at the time and I'm no longer with them - to my recollection, I was never asked for it at the time).

Fast forward to now-- I live in a completely different state, haven't thought about this incident in YEARS, and a few days ago I received a letter in the mail from a "legal solutions LLC" back in my home state where the incident occurred. They're claiming I owe my grandpa's insurance company $5469. The statute of limitations is 5 years, so I'm assuming this law firm bought up a bunch of old accounts from someone for a final attempt (the incident happened 4 years 11 months ago). To be completely honest, I truly have no idea if the debt is valid or not... I was always under the impression that insurance followed the driver, and that if I owed money to a company, they'd reach out to me first, in which case I'd defer them to my insurance company, but I never heard from anyone in this manner.

I did receive a strange phone call in 2016 from a woman who claimed to be calling from a debt collection agency and said I owed the aforementioned amount, but I told her she was mistaken and that I was indeed insured at the time. She goes, "Oh! Sorry about that, thanks!" and I never heard from her again.

Obviously I need to respond to this letter, but because I'm so close to the SOL, I'm not sure what my best move is. My gut was to request verification of the debt, but I've also read (over on the r/personalfinance wiki) that "it makes no sense to request verification on a debt that is at or near the SOL/reporting clock as doing so only increases the chance that Collections takes legal action while they still can".

I live 1800 miles away now, so going to court, if it came down to that, would be nearly impossible. Again, I truly have no idea if this debt is valid (it's never been on my credit report). If it is valid, I'm amazed that this is the first collections company to find my new home address in nearly five years.

tl;dr SOL is nearing, within weeks. -Do I send a letter denying the debt or do I request verification?
-Do I send it myself, from a template, or do I hire an attorney to send something?
-Is there anything else I should be doing?

I apologize for my ignorance and welcome any and all advice/suggestions! THANK YOU.