Interesting question ... I've never had fried mushy pea balls ... but eaten a lot of mushy peas. What did the recipe say to do?
I can see where after making you peas and cooling them you would make them into balls, place on a baking sheet, and place in the freezer for 30-minutes to an hour or so to firm up enough that they don't fall apart when you fry them - but not long enough to really freeze them solid.
Maybe ChefJen will see this and shed some more light on the problem.
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain