At least they didn't give it to him dry....gotta see the positive side lol
The alfalfa pellets soak pretty fast. If you have hot water in the barn, 10 minutes is all it takes. With cold water about an hour.
You could look for chopped alfalfa, doesn't require soaking, just a little water over it to make it stick.
I would at least try to talk to the BO and see if it could be done. If they give hay first, then grain, they could add water before giving hay, by the time they hayed everybody, it should be soaked.
If not, the chopped alfalfa. He likes it as hay, si I don't think he would refuse it together with his senior.
I know it's hard to work around other people, but it needs to be done. That's why I have my horses at home