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
Mountain rescue teams from Keswick, Cockermouth, and Wasdale have dealt with seven incidents since Friday.
Cyclists in west Cumbria are being encouraged to get their bikes marked and registered to help deter thieves.
A Cumbrian mill has been awarded £1.4 million by the Heritage Lottery Fund to help get it back in working order.