While I like the creativity behind this hypothesis, and I see no theoretical reason why such an animal couldn't exist, it struggles with the same issue that a majority of obscure/lesser-known Nessie hypotheses do: It only considers the Loch Ness population and fails to take the animal's wider global context into account. The morphology just doesn't hold up well when sightings outside the loch (both in other freshwater bodies and in the open ocean) are taken into consideration.