Shortfall means less than the expected amount. If the plaque says 1 million, you expect 1 million. If the box contains less than 1 million, that's a shortfall. However no one expects the plaque to say 1.55 Million even if that's what's actually in the box. A shortfall claim is an oxymoron - the claim is by definition the expected value, how can it ever be less than expected? In English we may say the claim was under, or low, but not short.

There are most certainly context rules that apply in this case which clearly indicate 50% shortfall to be referring to the money.

In english, a short claim is equivalent to a small claim.