Knowing the public key, he could at least have some hope, not that knowing public key could do magic, but at least we have some ideas which could be used to solve for private key. Of course if he is willing to spend money to hire a professional programmer to code the said ideas into an application/ tool.
Doing this is more practical than searching garbage, the hard drive is damaged by now due to humidity
I assume he has the private key. Otherwise he can’t be sure the funds weren’t already found and spent by someone else. Don’t kid yourself though, even with the public key there is no magic he can work and no additional hope that he would ever be able to get control of that lost Bitcoin ever again. He could look at it though.
https://youtu.be/0tMXLDVpPs8?t=1
1 year ago he has found the Blockchain address (visible in the video) and knows he mined 8000 BTC back in 2009
https://www.youtube.com/watch?v=cZr97E5PgzQ&t=250s