Doctor Andrew Brownlow, who carried out an autopsy on the whale, admitted he was not sure how the mammal came to swim up the Solway but concluded it might have simply been lost.
The juvenile male may have been following a shoal of fish or other food source and become disorientated.
The Fin Whale normally lives in the mid Atlantic.
The species spends the summer near the Arctic but comes further south in the winter.
More top news
The weekend looks promising for most of the region.
More than one in four children starting school in Cumbria have excess weight and obesity, according to Cumbria's Director of Public Health.
The 20-year-old from Workington is alleged to have kept a handwritten diary with detailed instructions on how to make pipe bombs and napalm.