What he (the dog) needs is to trust the husband inside the house and out. If it take food bribery, GO FOR IT. Use what he loves most. Most important, be patient. It does not matter how long it takes, as long as you are making forward progress.
Make sure when your wife returns, both of you work together as a team with him. When you go for walks, she can start with the leash and the dog between you, pass the leash between you and don't forget you food bribes (at least in the beginning.)
It will take time but that is on your side.
Here's a suggestion: There are three ways you can approach him. You can back up to him or approach him from your side (side-step). A frontal approach is more dominate and for him is a tough challenge. Eventually, you can do this but for now try the other two and see if it makes a difference.
Although dogs live in the moment, there is something that is triggered in his brain around men. Try not to take it personally, you have been nothing but kind and that is what he needs in order to trust you. He needs to know you are not there to hurt or harm him.
Best wishes on his rehab. Oh, I almost forgot, thank you for saving his life!
"From wet noses to wiggley butts, our dogs are not just dogs, they are family!" Luv-A-Bull.Denver