It does seem odd that they think a stranger may have come by and given the pellets as a treat. I would think it would have to be a pretty significant amount to expand to the point of causing death. Not just a few handfuls from a stranger wanting to give a treat. I think they are missing something here.
But yes, when I feed the shreds, I soak them. Mainly because I want to increase water intake this time of year too, since they don't particularly like the icy water in the pastures, and drink less.
"Keep a leg on each side and your mind in the middle"