a really good PC technician could attempt to recover those files
Well, I tried putting the hard disk into another computer to see if any partitions were accessible and the computer says the hard drive is unformatted.

I tell you that you'd not even have gotten the hard drives back out of the facility if you brought them into my old company
I know what you mean from a legal standpoint, but you have to understand the background of this company. It was a small family run business and I got hired 20 years ago because I was friends with the owner. When he passed in 2009 his wife took over ownership and left the running of the business to me. In fact, she asked me to keep a backup of the company data off site in case of fire, so I have their data at home anyways and she knows it so erasing the hard drive was pointless and was done for punitive reasons only.