is walters now shot?

Not sure.

Reasons why he may be shot:
I haven't seen anyone on the elite level quit the way he did. Duran quit for 'defiant macho' reasons. Decisions like that in life can psychologically alter you.
He blows up in weight between fights.

Reasons why he may not be shot:
If he doesn't want to see himself as the man who gave up, he will come back with a vengeance.
We've seen him badly hurt and wobbled vs Donaire's money shots, but Walters fought on like a warrior.
Walters still was that guy who went 27-0 (counting Sosa as a win) and looked damn impressive.
He's young enough to get away with blowing up in weight, and he was in amazing condition for a good month at least, before the fight.

He has some soul searching to do.