I agree ColinE - its a very poor clue, but I assumed that someone who put er in the clue rather than add something about " hesitantly" or " casualty" to suggest er , might also think the Loch Ness monster was in Loch Lomond.
As to whether redcrane has put er instead of ew - they have referenced it twice in the posting.
And " Marseille to Paris " can be read either way .