Translation:The man runs far away when he finds bread knives in the cabinet.
I think the use of "da" is according to point 2 at https://ordnet.dk/ddo/ordbog?select=da,3&query=da , or one of the points at https://ordnet.dk/ddo/ordbog?select=da,2&query=da. But the explanations are still a bit too challenging for me. It would be nice to have a native speaker comment.
"når" is used about repeated instances. So here it would indicate that the action of finding those knives in the cupboard is something that happens regularly and that the person runs away everytime. "Da" only indicates that the man runs away in this (hopefully) single instance.
If this sentence wants to say "The man runs far away EVERY TIME he finds bread knives in the cabinet", the correct connecting word is "når" and not "da".
But "da" can also mean "because". That's why the correct English translation could also be "The man runs far away BECAUSE he finds bread knives in the cabinet"