All law is purely semantic.
The semantic distinction may not have any legal bearing, however. It depends on the legal, not popular, acceptation of the two terms. To my way of thinking, misappropriation has more to do with the purpose for which something is used than its means of acquisition. For instance, to use tax revenues for non-statutory purposes might be misappropriation, but not theft per se, if there was no benefit to the perpetrator. If, however, the non-statutory purpose was to purchase a new car for the sheriff's daughter, and this was approved by some higher authority, that is both misappropriation and theft.